MILE Working Group R. Danyliw
Internet-Draft CERT
Obsoletes: 5070 (if approved) P. Stoecker
Intended status: Standards Track RSA
Expires: April 18, 2016 October 16, 2015
The Incident Object Description Exchange Format v2
draft-ietf-mile-rfc5070-bis-15
Abstract
The Incident Object Description Exchange Format (IODEF) defines a
data representation for sharing information commonly exchanged by
Computer Security Incident Response Teams (CSIRTs) about computer
security incidents. This document describes the information model
for the IODEF and provides an associated data model specified with
XML Schema.
Status of This Memo
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This Internet-Draft will expire on April 18, 2016.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1. Changes from 5070 . . . . . . . . . . . . . . . . . . . . 6
1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 7
1.3. Notations . . . . . . . . . . . . . . . . . . . . . . . . 8
1.4. About the IODEF Data Model . . . . . . . . . . . . . . . 8
1.5. About the IODEF Implementation . . . . . . . . . . . . . 9
2. IODEF Data Types . . . . . . . . . . . . . . . . . . . . . . 9
2.1. Integers . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2. Real Numbers . . . . . . . . . . . . . . . . . . . . . . 9
2.3. Characters and Strings . . . . . . . . . . . . . . . . . 10
2.4. Multilingual Strings . . . . . . . . . . . . . . . . . . 10
2.5. Bytes . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.6. Hexadecimal Bytes . . . . . . . . . . . . . . . . . . . . 11
2.7. Enumerated Types . . . . . . . . . . . . . . . . . . . . 11
2.8. Date-Time Strings . . . . . . . . . . . . . . . . . . . . 11
2.9. Timezone String . . . . . . . . . . . . . . . . . . . . . 11
2.10. Port Lists . . . . . . . . . . . . . . . . . . . . . . . 12
2.11. Postal Address . . . . . . . . . . . . . . . . . . . . . 12
2.12. Person or Organization . . . . . . . . . . . . . . . . . 12
2.13. Telephone and Fax Numbers . . . . . . . . . . . . . . . . 12
2.14. Email String . . . . . . . . . . . . . . . . . . . . . . 12
2.15. Uniform Resource Locator strings . . . . . . . . . . . . 13
2.16. Identifiers and Identifier References . . . . . . . . . . 13
3. The IODEF Data Model . . . . . . . . . . . . . . . . . . . . 13
3.1. IODEF-Document Class . . . . . . . . . . . . . . . . . . 13
3.2. Incident Class . . . . . . . . . . . . . . . . . . . . . 14
3.3. Common Attributes . . . . . . . . . . . . . . . . . . . . 18
3.3.1. restriction Attribute . . . . . . . . . . . . . . . . 18
3.3.2. observable-id Attribute . . . . . . . . . . . . . . . 19
3.4. IncidentID Class . . . . . . . . . . . . . . . . . . . . 19
3.5. AlternativeID Class . . . . . . . . . . . . . . . . . . . 20
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3.6. RelatedActivity Class . . . . . . . . . . . . . . . . . . 21
3.7. ThreatActor Class . . . . . . . . . . . . . . . . . . . . 22
3.8. Campaign Class . . . . . . . . . . . . . . . . . . . . . 23
3.9. AdditionalData Class . . . . . . . . . . . . . . . . . . 24
3.10. Contact Class . . . . . . . . . . . . . . . . . . . . . . 26
3.10.1. RegistryHandle Class . . . . . . . . . . . . . . . . 30
3.10.2. PostalAddress Class . . . . . . . . . . . . . . . . 31
3.10.3. Email Class . . . . . . . . . . . . . . . . . . . . 31
3.10.4. Telephone and Fax Classes . . . . . . . . . . . . . 32
3.11. Time Classes . . . . . . . . . . . . . . . . . . . . . . 32
3.11.1. StartTime Class . . . . . . . . . . . . . . . . . . 33
3.11.2. EndTime Class . . . . . . . . . . . . . . . . . . . 33
3.11.3. DetectTime Class . . . . . . . . . . . . . . . . . . 33
3.11.4. ReportTime Class . . . . . . . . . . . . . . . . . . 33
3.11.5. GenerationTime Class . . . . . . . . . . . . . . . . 33
3.11.6. DateTime . . . . . . . . . . . . . . . . . . . . . . 33
3.12. Discovery Class . . . . . . . . . . . . . . . . . . . . . 33
3.12.1. DetectionPattern Class . . . . . . . . . . . . . . . 35
3.13. Method Class . . . . . . . . . . . . . . . . . . . . . . 36
3.13.1. Reference Class . . . . . . . . . . . . . . . . . . 37
3.14. Assessment Class . . . . . . . . . . . . . . . . . . . . 38
3.14.1. SystemImpact Class . . . . . . . . . . . . . . . . . 40
3.14.2. BusinessImpact Class . . . . . . . . . . . . . . . . 43
3.14.3. TimeImpact Class . . . . . . . . . . . . . . . . . . 45
3.14.4. MonetaryImpact Class . . . . . . . . . . . . . . . . 47
3.14.5. Confidence Class . . . . . . . . . . . . . . . . . . 48
3.15. History Class . . . . . . . . . . . . . . . . . . . . . . 48
3.15.1. HistoryItem Class . . . . . . . . . . . . . . . . . 49
3.16. EventData Class . . . . . . . . . . . . . . . . . . . . . 51
3.16.1. Relating the Incident and EventData Classes . . . . 53
3.16.2. Cardinality of EventData . . . . . . . . . . . . . . 53
3.17. Expectation Class . . . . . . . . . . . . . . . . . . . . 54
3.18. Flow Class . . . . . . . . . . . . . . . . . . . . . . . 57
3.19. System Class . . . . . . . . . . . . . . . . . . . . . . 58
3.20. Node Class . . . . . . . . . . . . . . . . . . . . . . . 61
3.20.1. Address Class . . . . . . . . . . . . . . . . . . . 62
3.20.2. NodeRole Class . . . . . . . . . . . . . . . . . . . 63
3.20.3. Counter Class . . . . . . . . . . . . . . . . . . . 66
3.21. DomainData Class . . . . . . . . . . . . . . . . . . . . 68
3.21.1. RelatedDNS . . . . . . . . . . . . . . . . . . . . . 71
3.21.2. Nameservers Class . . . . . . . . . . . . . . . . . 71
3.21.3. DomainContacts Class . . . . . . . . . . . . . . . . 72
3.22. Service Class . . . . . . . . . . . . . . . . . . . . . . 73
3.22.1. ServiceName Class . . . . . . . . . . . . . . . . . 74
3.22.2. ApplicationHeader Class . . . . . . . . . . . . . . 75
3.22.3. Application Class . . . . . . . . . . . . . . . . . 77
3.22.4. SoftwareReference Class . . . . . . . . . . . . . . 78
3.23. OperatingSystem Class . . . . . . . . . . . . . . . . . . 79
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3.24. EmailData Class . . . . . . . . . . . . . . . . . . . . . 79
3.25. Record Class . . . . . . . . . . . . . . . . . . . . . . 80
3.25.1. RecordData Class . . . . . . . . . . . . . . . . . . 81
3.25.2. RecordPattern Class . . . . . . . . . . . . . . . . 82
3.25.3. RecordItem Class . . . . . . . . . . . . . . . . . . 84
3.26. WindowsRegistryKeysModified Class . . . . . . . . . . . . 84
3.26.1. Key Class . . . . . . . . . . . . . . . . . . . . . 85
3.27. CertificateData Class . . . . . . . . . . . . . . . . . . 86
3.27.1. Certificate Class . . . . . . . . . . . . . . . . . 86
3.28. FileData Class . . . . . . . . . . . . . . . . . . . . . 87
3.28.1. File Class . . . . . . . . . . . . . . . . . . . . . 88
3.29. HashData Class . . . . . . . . . . . . . . . . . . . . . 89
3.29.1. Hash Class . . . . . . . . . . . . . . . . . . . . . 91
3.29.2. FuzzyHash Class . . . . . . . . . . . . . . . . . . 91
3.30. SignatureData Class . . . . . . . . . . . . . . . . . . . 92
3.31. IndicatorData Class . . . . . . . . . . . . . . . . . . . 92
3.32. Indicator Class . . . . . . . . . . . . . . . . . . . . . 93
3.32.1. IndicatorID Class . . . . . . . . . . . . . . . . . 95
3.32.2. AlternativeIndicatorID Class . . . . . . . . . . . . 95
3.32.3. Observable Class . . . . . . . . . . . . . . . . . . 96
3.32.4. IndicatorExpression Class . . . . . . . . . . . . . 101
3.32.5. Expressions with IndicatorExpression . . . . . . . . 103
3.32.6. ObservableReference Class . . . . . . . . . . . . . 104
3.32.7. IndicatorReference Class . . . . . . . . . . . . . . 105
4. Processing Considerations . . . . . . . . . . . . . . . . . . 105
4.1. Encoding . . . . . . . . . . . . . . . . . . . . . . . . 105
4.2. IODEF Namespace . . . . . . . . . . . . . . . . . . . . . 106
4.3. Validation . . . . . . . . . . . . . . . . . . . . . . . 106
4.4. Incompatibilities with v1 . . . . . . . . . . . . . . . . 107
5. Extending the IODEF . . . . . . . . . . . . . . . . . . . . . 108
5.1. Extending the Enumerated Values of Attributes . . . . . . 108
5.1.1. Private Extension of Enumerated Values . . . . . . . 109
5.1.2. Public Extension of Enumerated Values . . . . . . . . 109
5.2. Extending Classes . . . . . . . . . . . . . . . . . . . . 109
5.3. Deconflicting Private Extensions . . . . . . . . . . . . 111
6. Internationalization Issues . . . . . . . . . . . . . . . . . 112
7. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 113
7.1. Minimal Example . . . . . . . . . . . . . . . . . . . . . 113
7.2. Indicators from a Campaign . . . . . . . . . . . . . . . 114
7.3. Incident Report . . . . . . . . . . . . . . . . . . . . . 115
8. The IODEF Schema . . . . . . . . . . . . . . . . . . . . . . 115
9. Security Considerations . . . . . . . . . . . . . . . . . . . 160
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 161
10.1. Namespace and Schema . . . . . . . . . . . . . . . . . . 161
10.2. Enumerated Value Registries . . . . . . . . . . . . . . 161
11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 164
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 164
12.1. Normative References . . . . . . . . . . . . . . . . . . 164
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12.2. Informative References . . . . . . . . . . . . . . . . . 166
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 167
1. Introduction
Organizations require help from other parties to mitigate malicious
activity targeting their network and to gain insight into potential
threats. This coordination might entail working with an ISP to
filter attack traffic, contacting a remote site to take down a bot-
network, or sharing watch-lists of known malicious IP addresses in a
consortium.
The Incident Object Description Exchange Format (IODEF) is a format
for representing computer security information commonly exchanged
between Computer Security Incident Response Teams (CSIRTs). It
provides an XML representation for conveying:
o cyber intelligence to characterize threats;
o cyber incident reports to document particular cyber security
events or relationships between events;
o cyber event mitigation to request proactive and reactive
mitigation approaches to cyber intelligence or incidents; and
o cyber information sharing meta-data so that these various classes
of information can be exchanged among parties.
The data model encodes information about hosts, networks, and the
services running on these systems; attack methodology and associated
forensic evidence; impact of the activity; and limited approaches for
documenting workflow.
The overriding purpose of the IODEF is to enhance the operational
capabilities of CSIRTs. Community adoption of the IODEF provides an
improved ability to resolve incidents and convey situational
awareness by simplifying collaboration and data sharing. This
structured format provided by the IODEF allows for:
o increased automation in processing of incident data, since the
resources of security analysts to parse free-form textual
documents will be reduced;
o decreased effort in normalizing similar data (even when highly
structured) from different sources; and
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o a common format on which to build interoperable tools for incident
handling and subsequent analysis, specifically when data comes
from multiple constituencies.
Coordinating with other CSIRTs is not strictly a technical problem.
There are numerous procedural, trust, and legal considerations that
might prevent an organization from sharing information. The IODEF
does not attempt to address them. However, operational
implementations of the IODEF will need to consider this broader
context.
Sections 3 and 8 specify the IODEF data model with text and an XML
schema. The types used by the data model are covered in Section 2.
Processing considerations, the handling of extensions, and
internationalization issues related to the data model are covered in
Sections 4, 5, and 6, respectively. Examples are listed in
Section 7. Section 1 provides the background for the IODEF, and
Section 9 documents the security considerations.
1.1. Changes from 5070
This document contains changes with respect to its predecessor
RFC5070.
o All of the RFC5070 Errata was implemented.
o Imported the xmlns:ds namespace to include digital signature hash
classes.
o The following classes were added to IODEF-Document:
AdditionalData.
o The following class and attribute was added to Incident:
IndicatorData and @status.
o The following classes were added to Incident and EventData:
GenerationTime and Discovery.
o The following classes and attributes were added to the Service
class: EmailData, DomainData, AssetID, ApplicationHeader @virtual,
and @ownership. Service@ip_protocol was renamed to @ip-protocol.
o The following classes were added to the Record class: HashData and
WindowsRegistryKeysModified.
o The following classes were added to the RelatedActivity class:
ThreatActor, Campaign, Confidence, Description, and
AdditionalData.
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o The following classes were added to Assessment: IncidentCategory,
SystemImpact, BusinessImpact, IntendedImpact and MitigatingFactor.
o The following classes were added to Node: PostalAddress and
DomainData. The following classes were removed from Node: Removed
NodeName and DateTime.
o The following classes were added to the Contact class:
ContactTitle.
o The following classes were added to Expectation and HistoryItem:
DefinedCOA.
o The following classes were added to Service: ServiceName
o The following classes were added to Reference: ReferenceName
(replaced Name).
o The following attributes were added to Counter: type and unit.
o Additional enumerated values were added to the following
attributes: @restriction, {Expectation, HistoryItem}@action,
NodeRole@category, Incident@purpose, Contact@role,
AdditionalData@dtype, System@spoofed.
o Added option for public extension of enumerated attributes with an
IANA registry and added @ext-restriction.
o Removed Impact class in favor of using SystemImpact and
IncidentCategory.
o iodef:MLStringType uses xml:lang and @translation-id.
o Incident/ReportTime and Assessment are longer mandatory.
o Incident/GenerateTime is mandatory.
1.2. Terminology
The key words "MUST," "MUST NOT," "REQUIRED," "SHALL," "SHALL NOT,"
"SHOULD," "SHOULD NOT," "RECOMMENDED," "MAY," and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
Definitions for some of the common computer security-related
terminology used in this document can be found in Section 2 of
[refs.requirements].
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1.3. Notations
The normative IODEF data model is specified with the text in
Section 3 and the XML schema in Section 8. To help in the
understanding of the data elements, Section 3 also depicts the
underlying information model using Unified Modeling Language (UML).
This abstract presentation of the IODEF is not normative.
For clarity in this document, the term "XML document" will be used
when referring generically to any instance of an XML document. The
term "IODEF document" will be used to refer to specific elements and
attributes of the IODEF schema. The terms "class" and "element" will
be used interchangeably to reference either the corresponding data
element in the information or data models, respectively.
1.4. About the IODEF Data Model
The IODEF data model is a data representation that provides a
framework for sharing information commonly exchanged by CSIRTs about
computer security incidents. A number of considerations were made in
the design of the data model.
o The data model serves as a transport format. Therefore, its
specific representation is not the optimal representation for on-
disk storage, long-term archiving, or in-memory processing.
o As there is no precise widely agreed upon definition for an
incident, the data model does not attempt to dictate one through
its implementation. Rather, a broad understanding is assumed in
the IODEF that is flexible enough to encompass most operators.
o Describing an incident for all definitions would require an
extremely complex data model. Therefore, the IODEF only intends
to be a framework to convey commonly exchanged incident
information. It ensures that there are ample mechanisms for
extensibility to support organization-specific information, and
techniques to reference information kept outside of the explicit
data model.
o The domain of security analysis is not fully standardized and must
rely on free-form textual descriptions. The IODEF attempts to
strike a balance between supporting this free-form content, while
still allowing automated processing of incident information.
o The IODEF is only one of several security relevant data
representations being standardized. Attempts were made to ensure
they were complementary. The data model of the Intrusion
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Detection Message Exchange Format [RFC4765] influenced the design
of the IODEF.
Further discussion of the desirable properties for the IODEF can be
found in the Requirements for the Format for Incident Information
Exchange (FINE) [refs.requirements].
1.5. About the IODEF Implementation
The IODEF implementation is specified as an Extensible Markup
Language (XML) [W3C.XML] Schema [W3C.SCHEMA].
Implementing the IODEF in XML provides numerous advantages. Its
extensibility makes it ideal for specifying a data encoding framework
that supports various character encodings. Likewise, the abundance
of related technologies (e.g., XSL, XPath, XML-Signature) makes for
simplified manipulation. However, XML is fundamentally a text
representation, which makes it inherently inefficient when binary
data must be embedded or large volumes of data must be exchanged.
2. IODEF Data Types
The various data elements of the IODEF data model are typed. This
section discusses these data types. When possible, native Schema
data types were adopted, but for more complicated formats, regular
expressions (see Appendix F of [W3C.SCHEMA.DTYPES]) or external
standards were used.
2.1. Integers
An integer is represented by the INTEGER data type. Integer data
MUST be encoded in Base 10.
The INTEGER data type is implemented as an "xs:integer" in
[W3C.SCHEMA.DTYPES].
2.2. Real Numbers
Real (floating-point) attributes are represented by the REAL data
type. Real data MUST be encoded in Base 10.
The REAL data type is implemented as an "xs:float" in
[W3C.SCHEMA.DTYPES].
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2.3. Characters and Strings
A single character is represented by the CHARACTER data type. A
character string is represented by the STRING data type. Special
characters must be encoded using entity references. See Section 4.1.
The CHARACTER and STRING data types are implemented as an "xs:string"
in [W3C.SCHEMA.DTYPES].
2.4. Multilingual Strings
A character string that needs to be represented in a language
different than the default encoding of the document is of the
ML_STRING data type.
ML_STRING data type is implemented as the "iodef:MLStringType" type
in the schema. This type extends the "xs:string" to include two
attributes. The body of any class that uses this type is the
multilingual string.
+------------------------+
| iodef:MLStringType |
+------------------------+
| ENUM xml:lang |
| STRING translation-id |
| |
+------------------------+
Figure 1: The iodef:MLStringType Type
Classes of the iodef:MLStringType type have two attributes:
xml:lang
Optional. ENUM. A language identifier per Section 2.12 of
[W3C.XML] whose values and form are described in [RFC5646]. The
interpretation of this code is described in Section 6.
translation-id
Optional. STRING. An identifier to relate other instances of
this class with the same parent as translations of this text. The
scope of this identifier is limited to all of the direct, peer
child classes of a given parent class.
Using this class enables representing translation of the same text in
multiple language. Each translation is a distinct instance of this
class with a common parent. This relationship between multiple
classes being translated instances of the same text is indicated by a
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common identifier set in the translation-id attribute. The language
of a given class of this type is set by the xml:lang attribute.
2.5. Bytes
A binary octet is represented by the BYTE data type. A sequence of
binary octets is represented by the BYTE[] data type. These octets
are encoded using base64.
The BYTE data type is implemented as an "xs:base64Binary" in
[W3C.SCHEMA.DTYPES].
2.6. Hexadecimal Bytes
A binary octet is represented by the HEXBIN (and HEXBIN[]) data type.
This octet is encoded as a character tuple consisting of two
hexadecimal digits.
The HEXBIN data type is implemented as an "xs:hexBinary" in
[W3C.SCHEMA.DTYPES].
2.7. Enumerated Types
Enumerated types are represented by the ENUM data type, and consist
of an ordered list of acceptable values. Each value has a
representative keyword. Within the IODEF schema, the enumerated type
keywords are used as attribute values.
The ENUM data type is implemented as a series of "xs:NMTOKEN" in the
schema.
2.8. Date-Time Strings
Date-time strings are represented by the DATETIME data type. Each
date-time string identifies a particular instant in time. Ranges are
not supported.
Date-time strings are formatted according to a subset of [ISO8601]
documented in [RFC3339].
The DATETIME data type is implemented as an "xs:dateTime" in the
schema.
2.9. Timezone String
A timezone offset from UTC is represented by the TIMEZONE data type.
It is formatted according to the following regular expression:
"Z|[\+\-](0[0-9]|1[0-4]):[0-5][0-9]".
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The TIMEZONE data type is implemented as an "xs:string" with a
regular expression constraint in [W3C.SCHEMA.DTYPES]. This regular
expression is identical to the timezone representation implemented in
an "xs:dateTime".
2.10. Port Lists
A list of network ports are represented by the PORTLIST data type. A
PORTLIST consists of a comma-separated list of numbers and ranges
(N-M means ports N through M, inclusive). It is formatted according
to the following regular expression: "\d+(\-\d+)?(,\d+(\-\d+)?)*".
For example, "2,5-15,30,32,40-50,55-60".
The PORTLIST data type is implemented as an "xs:string" with a
regular expression constraint in the schema.
2.11. Postal Address
A postal address is represented by the POSTAL data type. This data
type is an ML_STRING whose format is documented in Section 2.23 of
[RFC4519]. It defines a postal address as a free-form multi-line
string separated by the "$" character.
The POSTAL data type is implemented as an "xs:string" in the schema.
2.12. Person or Organization
The name of an individual or organization is represented by the NAME
data type. This data type is an ML_STRING whose format is documented
in Section 2.3 of [RFC4519].
The NAME data type is implemented as an "xs:string" in the schema.
2.13. Telephone and Fax Numbers
A telephone or fax number is represented by the PHONE data type. The
format of the PHONE data type is documented in Section 2.35 of
[RFC4519].
The PHONE data type is implemented as an "xs:string" in the schema.
2.14. Email String
An email address is represented by the EMAIL data type. The format
of the EMAIL data type is documented in Section 3.4.1 [RFC5322].
The EMAIL data type is implemented as an "xs:string" in the schema.
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2.15. Uniform Resource Locator strings
A uniform resource locator (URL) is represented by the URL data type.
The format of the URL data type is documented in [RFC3986].
The URL data type is implemented as an "xs:anyURI" in the schema.
2.16. Identifiers and Identifier References
An identifier unique to the Document is represented by the ID data
type. A reference to this identifier is represented by the IDREF
data type. The acceptable format of ID and IDREF is documented in
Section 3.3.8 and 3.3.9 of [W3C.SCHEMA.DTYPES].
The ID and IDREF data types are implemented as "xs:ID" and "xs:IDREF"
in the schema.
3. The IODEF Data Model
In this section, the individual components of the IODEF data model
will be discussed in detail. For each class, the semantics will be
described and the relationship with other classes will be depicted
with UML. When necessary, specific comments will be made about
corresponding definition in the schema in Section 8
3.1. IODEF-Document Class
The IODEF-Document class is the top level class in the IODEF data
model. All IODEF documents are an instance of this class.
+--------------------------+
| IODEF-Document |
+--------------------------+
| STRING version |<>--{1..*}--[ Incident ]
| ENUM xml:lang |<>--{0..*}--[ AdditionalData ]
| STRING format-id |
| STRING private-enum-name |
| STRING private-enum-id |
+--------------------------+
Figure 2: IODEF-Document Class
The aggregate class that constitute IODEF-Document is:
Incident
One or more. The information related to a single incident.
AdditionalData
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Zero or more. Mechanism by which to extend the data model. See
Section 3.9
The IODEF-Document class has three attributes:
version
Required. STRING. The IODEF specification version number to
which this IODEF document conforms. The value of this attribute
MUST be "2.00"
xml:lang
Optional. ENUM. A language identifier per Section 2.12 of
[W3C.XML] whose values and form are described in [RFC5646]. The
interpretation of this code is described in Section 6.
format-id
Optional. STRING. A free-form string to convey processing
instructions to the recipient of the document. Its semantics must
be negotiated out-of-band.
private-enum-name
Optional. STRING. A globally unique identifier for the CSIRT
generating the document to deconflict private extensions used in
the Document. The fully qualified domain name associated with the
CSIRT MUST be used as the identifier.
private-enum-id
Optional. STRING. An organizationally unique identifier for an
extension used in the Document. If this attribute is set, the
private-enum-name MUST also be set.
3.2. Incident Class
Every incident is represented by an instance of the Incident class.
This class provides a standardized representation for commonly
exchanged incident data.
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+-------------------------+
| Incident |
+-------------------------+
| ENUM purpose |<>----------[ IncidentID ]
| STRING ext-purpose |<>--{0..1}--[ AlternativeID ]
| ENUM status |<>--{0..*}--[ RelatedActivity ]
| STRING ext-status |<>--{0..1}--[ DetectTime ]
| ENUM xml:lang |<>--{0..1}--[ StartTime ]
| ENUM restriction |<>--{0..1}--[ EndTime ]
| STRING ext-restriction |<>--{0..1}--{ RecoveryTime ]
| STRING observable-id |<>--{0..1}--[ ReportTime ]
| |<>----------[ GenerationTime ]
| |<>--{0..*}--[ Description ]
| |<>--{0..*} [ Discovery ]
| |<>--{0..*}--[ Assessment ]
| |<>--{0..*}--[ Method ]
| |<>--{1..*}--[ Contact ]
| |<>--{0..*}--[ EventData ]
| |<>--{0..*}--[ IndicatorData ]
| |<>--{0..1}--[ History ]
| |<>--{0..*}--[ AdditionalData ]
+-------------------------+
Figure 3: The Incident Class
The aggregate classes that constitute Incident are:
IncidentID
One. An incident tracking number assigned to this incident by the
CSIRT that generated the IODEF document.
AlternativeID
Zero or one. The incident tracking numbers used by other CSIRTs
to refer to the incident described in the document.
RelatedActivity
Zero or more. Related activity and attribution of this activity.
DetectTime
Zero or one. The time the incident was first detected.
StartTime
Zero or one. The time the incident started.
EndTime
Zero or one. The time the incident ended.
RecoveryTime
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Zero or one. The time the site recovered from the incident.
ReportTime
Zero or one. The time the incident was reported.
GenerationTime
One. The time the content in this Incident class was generated.
Description
Zero or more. ML_STRING. A free-form textual description of the
incident.
Discovery
Zero or more. The means by which this incident was detected.
Assessment
Zero or more. A characterization of the impact of the incident.
Method
Zero or more. The techniques used by the intruder in the
incident.
Contact
One or more. Contact information for the parties involved in the
incident.
EventData
Zero or more. Description of the events comprising the incident.
IndicatorData
Zero or more. Description of indicators.
History
Zero or one. A log of significant events or actions that occurred
during the course of handling the incident.
AdditionalData
Zero or more. Mechanism by which to extend the data model.
The Incident class has eight attributes:
purpose
Required. ENUM. The purpose attribute represents the reason why
the IODEF document was created. It is closely related to the
Expectation class (Section 3.17). These values are maintained in
the "Incident-purpose" IANA registry per Table 1. This attribute
is defined as an enumerated list:
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1. traceback. The document was sent for trace-back purposes.
2. mitigation. The document was sent to request aid in
mitigating the described activity.
3. reporting. The document was sent to comply with reporting
requirements.
4. watch. The document was sent to convey indicators to watch
for particular activity.
5. other. The document was sent for purposes specified in the
Expectation class.
6. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-purpose
Optional. STRING. A means by which to extend the purpose
attribute. See Section 5.1.1.
status
Optional. ENUM. The status attribute conveys the state in a
workflow where the incident is currently found. These values are
maintained in the "Incident-status" IANA registry per Table 1.
This attribute is defined as an enumerated list:
1. new. The document is newly reported and has not been
actioned.
2. in-progress. The contents of this document are under
investigation.
3. forwarded. The document has been forwarded to another party
for handling.
4. resolved. The investigation into the activity in this
document has concluded.
5. future. The described activity has not yet been detected.
6. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-status
Optional. STRING. A means by which to extend the status
attribute. See Section 5.1.1.
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xml:lang
Optional. ENUM. A language identifier per Section 2.12 of
[W3C.XML] whose values and form are described in [RFC5646]. The
interpretation of this code is described in Section 6.
restriction
Optional. ENUM. See Section 3.3.1.
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
observable-id
Optional. ID. See Section 3.3.2.
3.3. Common Attributes
There are a number of recurring attributes used by the data model.
They are documented in this section.
3.3.1. restriction Attribute
The restriction attribute indicates the disclosure guidelines to
which the sender expects the recipient to adhere for the information
represented in this class and its children. This guideline provides
no security since there are no specified technical means to ensure
that the recipient of the document handles the information as the
sender requested.
The value of this attribute is logically inherited by the children of
this class. That is to say, the disclosure rules applied to this
class, also apply to its children.
It is possible to set a granular disclosure policy, since all of the
high-level classes (i.e., children of the Incident class) have a
restriction attribute. Therefore, a child can override the
guidelines of a parent class, be it to restrict or relax the
disclosure rules (e.g., a child has a weaker policy than an ancestor;
or an ancestor has a weak policy, and the children selectively apply
more rigid controls). The implicit value of the restriction
attribute for a class that did not specify one can be found in the
closest ancestor that did specify a value.
This attribute is defined as an enumerated value with a default value
of "private". Note that the default value of the restriction
attribute is only defined in the context of the Incident class. In
other classes where this attribute is used, no default is specified.
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These values are maintained in the "Restriction" IANA registry per
Table 1.
1. public. The information can be freely distributed without
restriction.
2. partner. The information may be shared within a closed
community of peers, partners, or affected parties, but cannot be
openly published.
3. need-to-know. The information may be shared only within the
organization with individuals that have a need to know.
4. private. The information may not be shared.
5. default. The information can be shared according to an
information disclosure policy pre-arranged by the communicating
parties.
6. white. Same as 'public'.
7. green. Same as 'partner'.
8. amber. Same as 'need-to-know'.
9. red. Same as 'private'.
10. ext-value. An escape value used to extend this attribute. See
Section 5.1.1.
3.3.2. observable-id Attribute
Information included in an incident report may be an observable
relevant to an indicator. The observable-id attribute provides a
unique identifier in the scope of the document for this observable.
This identifier can then be used to reference the observable with an
ObservableReference class to define an indicator in the IndicatorData
class.
3.4. IncidentID Class
The IncidentID class represents an incident tracking number that is
unique in the context of the CSIRT and identifies the activity
characterized in an IODEF Document. This identifier would serve as
an index into the CSIRT incident handling system. The combination of
the name attribute and the string in the element content MUST be a
globally unique identifier describing the activity. Documents
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generated by a given CSIRT MUST NOT reuse the same value unless they
are referencing the same incident.
+------------------------+
| IncidentID |
+------------------------+
| STRING |
| |
| STRING name |
| STRING instance |
| ENUM restriction |
| STRING ext-restriction |
+------------------------+
Figure 4: The IncidentID Class
The IncidentID class has four attributes:
name
Required. STRING. An identifier describing the CSIRT that
created the document. In order to have a globally unique CSIRT
name, the fully qualified domain name associated with the CSIRT
MUST be used.
instance
Optional. STRING. An identifier referencing a subset of the
named incident.
restriction
Optional. ENUM. See Section 3.3.1. The default value is
"public".
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
3.5. AlternativeID Class
The AlternativeID class lists the incident tracking numbers used by
CSIRTs, other than the one generating the document, to refer to the
identical activity described in the IODEF document. A tracking
number listed as an AlternativeID references the same incident
detected by another CSIRT. The incident tracking numbers of the
CSIRT that generated the IODEF document must never be considered an
AlternativeID.
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+------------------------+
| AlternativeID |
+------------------------+
| ENUM restriction |<>--{1..*}--[ IncidentID ]
| STRING ext-restriction |
+------------------------+
Figure 5: The AlternativeID Class
The aggregate class that constitutes AlternativeID is:
IncidentID
One or more. The incident tracking number of another CSIRT.
The AlternativeID class has two attributes:
restriction
Optional. ENUM. See Section 3.3.1.
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
3.6. RelatedActivity Class
The RelatedActivity class relates the information described in the
rest of the IODEF document to previously observed incidents or
activity; and allows attribution to a specific actor or campaign.
+------------------------+
| RelatedActivity |
+------------------------+
| ENUM restriction |<>--{0..*}--[ IncidentID ]
| STRING ext-restriction |<>--{0..*}--[ URL ]
| |<>--{0..*}--[ ThreatActor ]
| |<>--{0..*}--[ Campaign ]
| |<>--{0..1}--[ Confidence ]
| |<>--{0..*}--[ Description ]
| |<>--{0..*}--[ AdditionalData ]
+------------------------+
Figure 6: RelatedActivity Class
The aggregate classes that constitutes RelatedActivity are:
IncidentID
One or more. The incident tracking number of a related incident.
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URL
One or more. URL. A URL to activity related to this incident.
ThreatActor
One or more. The threat actor to whom the described activity is
attributed.
Campaign
One or more. The campaign of a given threat actor to whom the
described activity is attributed.
Confidence
Zero or one. An estimate of the confidence in attributing this
RelatedActivity to the event described in the document.
Description
Zero or more. ML_STRING. A description of how these
relationships were derived.
AdditionalData
Zero or more. A mechanism by which to extend the data model.
RelatedActivity MUST at least have one instance of IncidentID, URL,
ThreatActor, or Campaign.
The RelatedActivity class has two attributes:
restriction
Optional. ENUM. See Section 3.3.1.
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
3.7. ThreatActor Class
The ThreatActor class describes a given actor.
+------------------------+
| ThreatActor |
+------------------------+
| ENUM restriction |<>--{0..1}--[ ThreatActorID ]
| STRING ext-restriction |<>--{0..*}--[ Description ]
| |<>--{0..*}--[ AdditionalData ]
+------------------------+
Figure 7: ThreatActor Class
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The aggregate classes that constitutes ThreatActor are:
ThreatActorID
One or more. STRING. An identifier for the ThreatActor.
Description
One or more. ML_STRING. A description of the ThreatActor.
AdditionalData
Zero or more. A mechanism by which to extend the data model.
ThreatActor MUST have at least one instance of a ThreatActorID or
Description.
The ThreatActor class has two attributes:
restriction
Optional. ENUM. See Section 3.3.1.
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
3.8. Campaign Class
The Campaign class describes a campaign of attacks by a threat actor.
+------------------------+
| Campaign |
+------------------------+
| ENUM restriction |<>--{0..1}--[ CampaignID ]
| STRING ext-restriction |<>--{0..*}--[ Description ]
| |<>--{0..*}--[ AdditionalData ]
+------------------------+
Figure 8: Campaign Class
The aggregate classes that constitutes Campaign are:
CampaignID
One or more. STRING. An identifier for the Campaign.
Description
One or more. ML_STRING. A description of the Campaign.
AdditionalData
Zero or more. A mechanism by which to extend the data model.
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Campaign MUST have at least one instance of a Campaign or
Description.
The Campaign class has two attributes:
restriction
Optional. ENUM. See Section 3.3.1.
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
3.9. AdditionalData Class
The AdditionalData class serves as an extension mechanism for
information not otherwise represented in the data model. For
relatively simple information, atomic data types (e.g., integers,
strings) are provided with a mechanism to annotate their meaning.
The class can also be used to extend the data model (and the
associated Schema) to support proprietary extensions by encapsulating
entire XML documents conforming to another Schema. A detailed
discussion for extending the data model and the schema can be found
in Section 5.
Unlike XML, which is self-describing, atomic data must be documented
to convey its meaning. This information is described in the
'meaning' attribute. Since these description are outside the scope
of the specification, some additional coordination may be required to
ensure that a recipient of a document using the AdditionalData
classes can make sense of the custom extensions.
+------------------------+
| AdditionalData |
+------------------------+
| ANY |
| |
| ENUM dtype |
| STRING ext-dtype |
| STRING meaning |
| STRING formatid |
| ENUM restriction |
| STRING ext-restriction |
+------------------------+
Figure 9: The AdditionalData Class
The AdditionalData class has six attributes:
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dtype
Required. ENUM. The data type of the element content. The
permitted values for this attribute are shown below. The default
value is "string". These values are maintained in the
"AdditionalData-dtype" IANA registry per Table 1.
1. boolean. The element content is of type BOOLEAN.
2. byte. The element content is of type BYTE.
3. bytes. The element content is of type HEXBIN.
4. character. The element content is of type CHARACTER.
5. date-time. The element content is of type DATETIME.
6. ntpstamp. Same as date-time.
7. integer. The element content is of type INTEGER.
8. portlist. The element content is of type PORTLIST.
9. real. The element content is of type REAL.
10. string. The element content is of type STRING.
11. file. The element content is a base64 encoded binary file
encoded as a BYTE[] type.
12. path. The element content is a file-system path encoded as a
STRING type.
13. frame. The element content is a layer-2 frame encoded as a
HEXBIN type.
14. packet. The element content is a layer-3 packet encoded as a
HEXBIN type.
15. ipv4-packet. The element content is an IPv4 packet encoded
as a HEXBIN type.
16. ipv6-packet. The element content is an IPv6 packet encoded
as a HEXBIN type.
17. url. The element content is of type URL.
18. csv. The element content is a common separated value (CSV)
list per Section 2 of [RFC4180] encoded as a STRING type.
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19. winreg. The element content is a Windows registry key
encoded as a STRING type.
20. xml. The element content is XML. See Section 5.
21. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-dtype
Optional. STRING. A means by which to extend the dtype
attribute. See Section 5.1.1.
meaning
Optional. STRING. A free-form description of the element
content.
formatid
Optional. STRING. An identifier referencing the format and
semantics of the element content.
restriction
Optional. ENUM. See Section 3.3.1.
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
3.10. Contact Class
The Contact class describes contact information for organizations and
personnel involved in the incident. This class allows for the naming
of the involved party, specifying contact information for them, and
identifying their role in the incident.
People and organizations are treated interchangeably as contacts; one
can be associated with the other using the recursive definition of
the class (the Contact class is aggregated into the Contact class).
The 'type' attribute disambiguates the type of contact information
being provided.
The inheriting definition of Contact provides a way to relate
information without requiring the explicit use of identifiers in the
classes or duplication of data. A complete point of contact is
derived by a particular traversal from the root Contact class to the
leaf Contact class. As such, multiple points of contact might be
specified in a single instance of a Contact class. Each child
Contact class logically inherits contact information from its
ancestors.
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+------------------------+
| Contact |
+------------------------+
| ENUM role |<>--{0..*}--[ ContactName ]
| STRING ext-role |<>--{0..*}--[ ContactTitle ]
| ENUM type |<>--{0..*}--[ Description ]
| STRING ext-type |<>--{0..*}--[ RegistryHandle ]
| ENUM restriction |<>--{0..1}--[ PostalAddress ]
| STRING ext-restriction |<>--{0..*}--[ Email ]
| |<>--{0..*}--[ Telephone ]
| |<>--{0..1}--[ Fax ]
| |<>--{0..1}--[ Timezone ]
| |<>--{0..*}--[ Contact ]
| |<>--{0..*}--[ AdditionalData ]
+------------------------+
Figure 10: The Contact Class
The aggregate classes that constitute the Contact class are:
ContactName
Zero or more. ML_STRING. The name of the contact. The contact
may either be an organization or a person. The type attribute
disambiguates the semantics.
ContactTitle
Zero or more. ML_STRING. The title for the individual named in
the ContactName.
Description
Zero or more. ML_STRING. A free-form description of this
contact. In the case of a person, this is often the
organizational title of the individual.
RegistryHandle
Zero or more. A handle name into the registry of the contact.
PostalAddress
Zero or one. The postal address of the contact.
Email
Zero or more. The email address of the contact.
Telephone
Zero or more. The telephone number of the contact.
Fax
Zero or one. The facsimile telephone number of the contact.
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Timezone
Zero or one. TIMEZONE. The timezone in which the contact resides
formatted according to Section 2.9.
Contact
Zero or more. A Contact instance contained within another Contact
instance inherits the values of the parent(s). This recursive
definition can be used to group common data pertaining to multiple
points of contact and is especially useful when listing multiple
contacts at the same organization.
AdditionalData
Zero or more. A mechanism by which to extend the data model.
At least one of the aggregate classes MUST be present in an instance
of the Contact class. This is not enforced in the IODEF schema as
there is no simple way to accomplish it.
The Contact class has six attributes:
role
Required. ENUM. Indicates the role the contact fulfills. This
attribute is defined as an enumerated list. These values are
maintained in the "Contact-role" IANA registry per Table 1.
1. creator. The entity that generate the document.
2. reporter. The entity that reported the information.
3. admin. An administrative contact or business owner for an
asset or organization.
4. tech. An entity responsible for the day-to-day management of
technical issues for an asset or organization.
5. provider. An external hosting provider for an asset.
6. zone. An entity with authority over a DNS zone.
7. user. An end-user of an asset or part of an organization.
8. billing. An entity responsible for billing issues for an
asset or organization.
9. legal. An entity responsible for legal issue related to an
asset or organization.
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10. irt. An entity responsible for handling security issues for
an asset or organization.
11. abuse. An entity responsible for handling abuse originating
from an asset or organization.
12. cc. An entity that is to be kept informed about the events
related to an asset or organization.
13. cc-irt. A CSIRT or information sharing organization
coordinating activity related to an asset or organization.
14. leo. A law enforcement organization supporting the
investigation of activity affecting an asset or organization.
15. vendor. The vendor that produces an asset.
16. vendor-support. A vendor that provides services.
17. victim. A victim in the incident.
18. victim-notified. A victim in the incident who has been
notified.
19. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-role
Optional. STRING. A means by which to extend the role attribute.
See Section 5.1.1.
type
Required. ENUM. Indicates the type of contact being described.
This attribute is defined as an enumerated list. These values are
maintained in the "Contact-type" IANA registry per Table 1.
1. person. The information for this contact references an
individual.
2. organization. The information for this contact references an
organization.
3. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-type
Optional. STRING. A means by which to extend the type attribute.
See Section 5.1.1.
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restriction
Optional. ENUM. See Section 3.3.1.
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
3.10.1. RegistryHandle Class
The RegistryHandle class represents a handle into an Internet
registry or community-specific database. The handle is specified in
the element content and the type attribute specifies the database.
+---------------------+
| RegistryHandle |
+---------------------+
| STRING |
| |
| ENUM registry |
| STRING ext-registry |
+---------------------+
Figure 11: The RegistryHandle Class
The RegistryHandle class has two attributes:
registry
Required. ENUM. The database to which the handle belongs. These
values are maintained in the "RegistryHandle-registry" IANA
registry per Table 1. The possible values are:
1. internic. Internet Network Information Center
2. apnic. Asia Pacific Network Information Center
3. arin. American Registry for Internet Numbers
4. lacnic. Latin-American and Caribbean IP Address Registry
5. ripe. Reseaux IP Europeens
6. afrinic. African Internet Numbers Registry
7. local. A database local to the CSIRT
8. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
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ext-registry
Optional. STRING. A means by which to extend the registry
attribute. See Section 5.1.1.
3.10.2. PostalAddress Class
The PostalAddress class specifies a postal address formatted
according to the POSTAL data type (Section 2.11).
+---------------------+
| PostalAddress |
+---------------------+
| POSTAL |
| |
| STRING meaning |
| ENUM xml:lang |
+---------------------+
Figure 12: The PostalAddress Class
The PostalAddress class has two attributes:
meaning
Optional. STRING. A free-form description of the element
content.
xml:lang
Optional. ENUM. A language identifier per Section 2.12 of
[W3C.XML] whose values and form are described in [RFC5646]. The
interpretation of this code is described in Section 6.
3.10.3. Email Class
The Email class specifies an email address formatted according to
EMAIL data type (Section 2.14).
+--------------+
| Email |
+--------------+
| EMAIL |
| |
| ENUM meaning |
+--------------+
Figure 13: The Email Class
The Email class has one attribute:
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meaning
Optional. ENUM. A free-form description of the element content.
3.10.4. Telephone and Fax Classes
The Telephone and Fax classes specify a voice or fax telephone number
respectively, and are formatted according to PHONE data type
(Section 2.13).
+--------------------+
| {Telephone | Fax } |
+--------------------+
| PHONE |
| |
| ENUM meaning |
+--------------------+
Figure 14: The Telephone and Fax Classes
The Telephone class has one attribute:
meaning
Optional. ENUM. A free-form description of the element content
(e.g., hours of coverage for a given number).
3.11. Time Classes
The data model uses six different classes to represent a timestamp.
Their definition is identical, but each has a distinct name to convey
a difference in semantics.
The element content of each class is a timestamp formatted according
to the DATETIME data type (see Section 2.8).
+-----------------+
| StartTime |
| EndTime |
| ReportTime |
| DetectTime |
| GenerationTime |
| DateTime |
+-----------------+
| DATETIME |
+-----------------+
Figure 15: The Time Classes
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3.11.1. StartTime Class
The StartTime class represents the time the incident began.
3.11.2. EndTime Class
The EndTime class represents the time the incident ended.
3.11.3. DetectTime Class
The DetectTime class represents the time the first activity of the
incident was detected.
3.11.4. ReportTime Class
The ReportTime class represents the time the incident was reported.
3.11.5. GenerationTime Class
The GenerationTime class represents the time when the IODEF document
was produced. This timestamp MUST be the time at which the IODEF
document was generated.
3.11.6. DateTime
The DateTime class is a generic representation of a timestamp. Infer
its semantics from the parent class in which it is aggregated.
3.12. Discovery Class
The Discovery class describes how an incident was detected.
+------------------------+
| Discovery |
+------------------------+
| ENUM source |<>--{0..*}--[ Description ]
| STRING ext-source |<>--{0..*}--[ Contact ]
| ENUM restriction |<>--{0..*}--[ DetectionPattern ]
| STRING ext-restriction |
+------------------------+
Figure 16: The Discovery Class
The Discovery class is composed of three aggregate classes.
Description
Zero or more. ML_STRING. A free-form text description of how
this incident was detected.
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Contact
Zero or more. Contact information for the party that discovered
the incident.
DetectionPattern
Zero or more. Describes an application-specific configuration
that detected the incident.
The Discovery class has four attribute:
source
Optional. ENUM. Categorizes the techniques used to discover the
incident. These values are partially derived from Table 3-1 of
[NIST800.61rev2]. These values are maintained in the "Discovery-
source" IANA registry per Table 1.
1. nidps. Network Intrusion Detection or Prevention system.
2. hips. Host-based Intrusion Prevention system.
3. siem. Security Information and Event Management System.
4. av. Antivirus or and antispam software.
5. third-party-monitoring. Contracted third-party monitoring
service.
6. incident. The activity was discovered while investigating an
unrelated incident.
7. os-log. Operating system logs.
8. application-log. Application logs.
9. device-log. Network device logs.
10. network-flow. Network flow analysis.
11. passive-dns. Passive DNS analysis.
12. investigation. Manual investigation initiated based on
notification of a new vulnerability or exploit.
13. audit. Security audit.
14. internal-notification. A party within the organization
reported the activity
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15. external-notification. A party outside of the organization
reported the activity.
16. leo. A law enforcement organization notified the victim
organization.
17. partner. A customer or business partner reported the
activity to the victim organization.
18. actor. The threat actor directly or indirectly reported this
activity to the victim organization.
19. unknown. Unknown detection approach.
20. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-source
Optional. STRING. A means by which to extend the source
attribute. See Section 5.1.1.
restriction
Optional. ENUM. See Section 3.3.1.
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
3.12.1. DetectionPattern Class
The DetectionPattern class describes a configuration or signature
that can be used by an IDS/IPS, SIEM, anti-virus, end-point
protection, network analysis, malware analysis, or host forensics
tool to identify a particular phenomenon. This class requires the
identification of the target application and allows the configuration
to be describes in either free-form or machine readable form.
+------------------------+
| DetectionPattern |
+------------------------+
| ENUM restriction |<>----------[ Application ]
| STRING ext-restriction |<>--{0..*}--[ Description ]
| |<>--{0..*}--[ DetectionConfiguration ]
+------------------------+
Figure 17: The DetectionPattern Class
The DetectionPattern class is composed of three aggregate classes.
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Application
One. The application for which the DetectionConfiguration or
Description is being provided.
Description
Zero or more. ML_STRING. A free-form text description of how to
use the Application or provided DetectionConfiguration.
DetectionConfiguration
Zero or more. STRING. A machine consumable configuration to find
a pattern of activity.
Either an instance of the Description or DetectionConfiguration class
MUST be present.
The DetectionPattern class has two attributes:
restriction
Optional. ENUM. See Section 3.3.1.
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
3.13. Method Class
The Method class describes the tactics, techniques, procedures or
underlying issue used by the intruder in the incident. This class
consists of both a list of references describing the attack methods
and weaknesses and a free form description.
+------------------------+
| Method |
+------------------------+
| ENUM restriction |<>--{0..*}--[ Reference ]
| STRING ext-restriction |<>--{0..*}--[ Description ]
| |<>--{0..*}--[ sci:AttackPattern ]
| |<>--{0..*}--[ sci:Vulnerability ]
| |<>--{0..*}--[ sci:Weakness ]
| |<>--{0..*}--[ AdditionalData ]
+------------------------+
Figure 18: The Method Class
The Method class is composed of six aggregate classes.
enum:Reference
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Zero or more. A reference to a vulnerability, malware sample,
advisory, or analysis of an attack technique.
Description
Zero or more. ML_STRING. A free-form text description of
techniques, tactics, or procedures used by the intruder.
sci:AttackPattern
Zero or more. A reference to an pattern of attack or exploitation
per [RFC-SCI]
sci:Vulnerability
Zero or more. A reference to a vulnerability per [RFC-SCI]
sci:Weakness
Zero or more. A reference to the exploited weakness per [RFC-SCI]
AdditionalData
Zero or more. A mechanism by which to extend the data model.
An instance of one of these child MUST be present.
The Method class has two attributes:
restriction
Optional. ENUM. See Section 3.3.1.
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
3.13.1. Reference Class
The Reference class is an external reference to relevant information
such a vulnerability, IDS alert, malware sample, advisory, or attack
technique. A reference consists of a name, a URL to this reference,
and an optional description.
+-------------------------+
| Reference |
+-------------------------+
| ID observable-id |<>--{0..1}--[ enum:ReferenceName ]
| |<>--{0..*}--[ URL ]
| |<>--{0..*}--[ Description ]
+-------------------------+
Figure 19: The Reference Class
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The aggregate classes that constitute Reference:
ReferenceName
Zero or one. Reference identifier per [RFC-ENUM].
URL
Zero or more. URL. A URL associated with the reference.
Description
Zero or more. ML_STRING. A free-form text description of this
reference.
At least one of these classes MUST be present.
The Reference class has one attribute.
observable-id
Optional. ID. See Section 3.3.2.
3.14. Assessment Class
The Assessment class describes the repercussions of the incident to
the victim.
+-------------------------+
| Assessment |
+-------------------------+
| ENUM occurrence |<>--{0..*}--[ IncidentCategory ]
| ENUM restriction |<>--{0..*}--[ SystemImpact ]
| STRING ext-restriction |<>--{0..*}--[ BusinessImpact ]
| ID observable-id |<>--{0..*}--[ TimeImpact ]
| |<>--{0..*}--[ MonetaryImpact ]
| |<>--{0..*}--[ IntendedImpact ]
| |<>--{0..*}--[ Counter ]
| |<>--{0..*}--[ MitigatingFactor ]
| |<>--{0..*}--[ Cause ]
| |<>--{0..1}--[ Confidence ]
| |<>--{0..*}--[ AdditionalData ]
+-------------------------+
Figure 20: Assessment Class
The aggregate classes that constitute Assessment are:
IncidentCategory
Zero or more. ML_STRING. A free-form text description
categorizing the type of Incident.
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SystemImpact
Zero or more. Technical characterization of the impact of the
activity on the victim's enterprise.
BusinessImpact
Zero or more. Impact of the activity on the business functions of
the victim organization.
TimeImpact
Zero or more. Impact of the activity measured with respect to
time.
MonetaryImpact
Zero or more. Impact of the activity measured with respect to
financial loss.
IntendedImpact
Zero or more. Intended impact to the victim by the attacker.
Identically defined as Section 3.14.2 but describes intent rather
than the realized impact.
Counter
Zero or more. A counter with which to summarize the magnitude of
the activity.
MitigatingFactor
Zero or more. ML_STRING. A description of a mitigating factor an
impact.
Cause
Zero or more. ML_STRING. A description of the underlying cause
of the impact.
Confidence
Zero or one. An estimate of confidence in the assessment.
AdditionalData
Zero or more. A mechanism by which to extend the data model.
A least one instance of the possible three impact classes (i.e.,
Impact, TimeImpact, or MonetaryImpact) MUST be present.
The Assessment class has four attributes:
occurrence
Optional. ENUM. Specifies whether the assessment is describing
actual or potential outcomes.
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1. actual. This assessment describes activity that has occurred.
2. potential. This assessment describes potential activity that
might occur.
restriction
Optional. ENUM. See Section 3.3.1.
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
observable-id
Optional. ID. See Section 3.3.2.
3.14.1. SystemImpact Class
The SystemImpact class describes the technical impact of the incident
to the systems on the network.
This class is based on [RFC4765].
+-----------------------+
| SystemImpact |
+-----------------------+
| ML_STRING |
| |
| ENUM xml:lang |
| STRING translation-id |
| ENUM severity |
| ENUM completion |
| ENUM type |
| STRING ext-type |
+-----------------------+
Figure 21: SystemImpact Class
The element content will be a free-form textual description of the
impact.
The SystemImpact class has six attributes:
xml:lang
Optional. ENUM. A language identifier. See Section 6.
translation-id
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Optional. STRING. An identifier to relate other instances of
this class as translations of this text. See Section 6.
severity
Optional. ENUM. An estimate of the relative severity of the
activity. The permitted values are shown below. There is no
default value.
1. low. Low severity
2. medium. Medium severity
3. high. High severity
completion
Optional. ENUM. An indication whether the described activity was
successful. The permitted values are shown below. There is no
default value.
1. failed. The attempted activity was not successful.
2. succeeded. The attempted activity succeeded.
type
Required. ENUM. Classifies the impact. The permitted values are
shown below. The default value is "unknown". These values are
maintained in the "SystemImpact-type" IANA registry per Table 1.
1. takeover-account. Control was taken of a given account
(e.g., a social media account).
2. takeover-service. Control was taken of a given service.
3. takeover-system. Control was taken of a given system.
4. cps-manipulation. A cyber physical system was manipulated.
5. cps-damage. A cyber physical system was damaged.
6. availability-data. Access to particular data was degraded or
denied.
7. availability-account. Access to an account was degraded or
denied.
8. availability-service. Access to a service was degraded or
denied.
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9. availability-system. Access to a system was degraded or
denied.
10. damaged-system. Hardware on a system was irreparably
damaged.
11. damaged-data. Data on a system was deleted.
12. breach-proprietary. Sensitive or proprietary information was
accessed or exfiltrated.
13. breach-privacy. Personally identifiable information was
accessed or exfiltrated.
14. breach-credential. Credential information was accessed or
exfiltrated.
15. breach-configuration. System configuration or data inventory
was access or exfiltrated.
16. integrity-data. Data on the system was modified.
17. integrity-configuration. Application or system configuration
was modified.
18. integrity-hardware. Firmware of a hardware component was
modified.
19. traffic-redirection. Network traffic on the system was
redirected
20. monitoring-traffic. Network traffic emerging from a host was
monitored.
21. monitoring-host. System activity (e.g., running processes,
keystrokes) were monitored.
22. policy. Activity violated the system owner's acceptable use
policy.
23. unknown. The impact is unknown.
24. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-type
Optional. STRING. A means by which to extend the type attribute.
See Section 5.1.1.
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3.14.2. BusinessImpact Class
The BusinessImpact class describes and characterizes the degree to
which the function of the organization was impacted by the Incident.
The element body describes the impact to the organization as a free-
form text string. The two attributes characterize the impact.
+-------------------------+
| BusinessImpact |
+-------------------------+
| ML_STRING |
| |
| ENUM xml:lang |
| STRING translation-id |
| ENUM severity |
| STRING ext-severity |
| ENUM type |
| STRING ext-type |
+-------------------------+
Figure 22: BusinessImpact Class
The element content will be a free-form textual description of the
impact to the organization.
The BusinessImpact class has four attributes:
xml:lang
Optional. ENUM. A language identifier. See Section 6.
translation-id
Optional. STRING. An identifier to relate other instances of
this class as translations of this text. See Section 6.
severity
Optional. ENUM. Characterizes the severity of the incident on
business functions. The permitted values are shown below. They
were derived from Table 3-2 of [NIST800.61rev2]. The default
value is "unknown". These values are maintained in the
"BusinessImpact-severity" IANA registry per Table 1.
1. none. No effect to the organization's ability to provide all
services to all users.
2. low. Minimal effect as the organization can still provide all
critical services to all users but has lost efficiency.
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3. medium. The organization has lost the ability to provide a
critical service to a subset of system users.
4. high. The organization is no longer able to provide some
critical services to any users.
5. unknown. The impact is not known.
6. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-severity
Optional. STRING. A means by which to extend the severity
attribute. See Section 5.1.1.
type
Required. ENUM. Characterizes the effect this incident had on
the business. The permitted values are shown below. There is no
default value. These values are maintained in the
"BusinessImpact-type" IANA registry per Table 1.
1. breach-proprietary. Sensitive or proprietary information was
accessed or exfiltrated.
2. breach-privacy. Personally identifiable information was
accessed or exfiltrated.
3. breach-credential. Credential information was accessed or
exfiltrated.
4. loss-of-integrity. Sensitive or proprietary information was
changed or deleted.
5. loss-of-service. Service delivery was disrupted.
6. theft-financial. Money was stolen.
7. theft-service. Services were misappropriated.
8. degraded-reputation. The reputation of the organization's
brand was diminished.
9. asset-damage. A cyber-physical system was damaged.
10. asset-manipulation. A cyber-physical system was manipulated.
11. legal. The incident resulted in legal or regulatory action.
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12. extortion. The incident resulted in actors extorting the
victim organization.
13. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-type
Optional. STRING. A means by which to extend the type attribute.
See Section 5.1.1.
3.14.3. TimeImpact Class
The TimeImpact class describes the impact of the incident on an
organization as a function of time. It provides a way to convey down
time and recovery time.
+---------------------+
| TimeImpact |
+---------------------+
| REAL |
| |
| ENUM severity |
| ENUM metric |
| STRING ext-metrics |
| ENUM duration |
| STRING ext-duration |
+---------------------+
Figure 23: TimeImpact Class
The element content is a positive, floating point (REAL) number
specifying a unit of time. The duration and metric attributes will
imply the semantics of the element content.
The TimeImpact class has five attributes:
severity
Optional. ENUM. An estimate of the relative severity of the
activity. The permitted values are shown below. There is no
default value.
1. low. Low severity
2. medium. Medium severity
3. high. High severity
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metric
Required. ENUM. Defines the metric in which the time is
expressed. The permitted values are shown below. There is no
default value. These values are maintained in the "TimeImpact-
metric" IANA registry per Table 1.
1. labor. Total staff-time to recovery from the activity (e.g.,
2 employees working 4 hours each would be 8 hours).
2. elapsed. Elapsed time from the beginning of the recovery to
its completion (i.e., wall-clock time).
3. downtime. Duration of time for which some provided service(s)
was not available.
4. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-metric
Optional. STRING. A means by which to extend the metric
attribute. See Section 5.1.1.
duration
Optional. ENUM. Defines a unit of time, that when combined with
the metric attribute, fully describes a metric of impact that will
be conveyed in the element content. The permitted values are
shown below. The default value is "hour". These values are
maintained in the "TimeImpact-duration" IANA registry per Table 1.
1. second. The unit of the element content is seconds.
2. minute. The unit of the element content is minutes.
3. hour. The unit of the element content is hours.
4. day. The unit of the element content is days.
5. month. The unit of the element content is months.
6. quarter. The unit of the element content is quarters.
7. year. The unit of the element content is years.
8. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-duration
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Optional. STRING. A means by which to extend the duration
attribute. See Section 5.1.1.
3.14.4. MonetaryImpact Class
The MonetaryImpact class describes the financial impact of the
activity on an organization. For example, this impact may consider
losses due to the cost of the investigation or recovery, diminished
productivity of the staff, or a tarnished reputation that will affect
future opportunities.
+------------------+
| MonetaryImpact |
+------------------+
| REAL |
| |
| ENUM severity |
| STRING currency |
+------------------+
Figure 24: MonetaryImpact Class
The element content is a positive, floating point number (REAL)
specifying a unit of currency described in the currency attribute.
The MonetaryImpact class has two attributes:
severity
Optional. ENUM. An estimate of the relative severity of the
activity. The permitted values are shown below. There is no
default value.
1. low. Low severity
2. medium. Medium severity
3. high. High severity
currency
Optional. STRING. Defines the currency in which the monetary
impact is expressed. The permitted values are defined in "Codes
for the representation of currencies and funds" of [ISO4217].
There is no default value.
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3.14.5. Confidence Class
The Confidence class represents a best estimate of the validity and
accuracy of the described impact (see Section 3.14) of the incident
activity. This estimate can be expressed as a category or a numeric
calculation.
This class if based upon [RFC4765].
+------------------+
| Confidence |
+------------------+
| REAL |
| |
| ENUM rating |
+------------------+
Figure 25: Confidence Class
The element content expresses a numerical assessment in the
confidence of the data when the value of the rating attribute is
"numeric". Otherwise, this element MUST be empty.
The Confidence class has one attribute.
rating
Required. ENUM. A rating of the analytical validity of the
specified Assessment. The permitted values are shown below.
There is no default value.
1. low. Low confidence in the validity.
2. medium. Medium confidence in the validity.
3. high. High confidence in the validity.
4. numeric. The element content contains a number that conveys
the confidence of the data. The semantics of this number
outside the scope of this specification.
5. unknown. The confidence rating value is not known.
3.15. History Class
The History class is a log of the significant events or actions
performed by the involved parties during the course of handling the
incident.
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The level of detail maintained in this log is left up to the
discretion of those handling the incident.
+------------------------+
| History |
+------------------------+
| ENUM restriction |<>--{1..*}--[ HistoryItem ]
| STRING ext-restriction |
+------------------------+
Figure 26: The History Class
The class that constitutes History is:
HistoryItem
One or many. Entry in the history log of significant events or
actions performed by the involved parties.
The History class has two attributes:
restriction
Optional. ENUM. See Section 3.3.1. The default value is
"default".
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
3.15.1. HistoryItem Class
The HistoryItem class is an entry in the History (Section 3.15) log
that documents a particular action or event that occurred in the
course of handling the incident. The details of the entry are a
free-form description, but each can be categorized with the type
attribute.
+-------------------------+
| HistoryItem |
+-------------------------+
| ENUM restriction |<>----------[ DateTime ]
| STRING ext-restriction |<>--{0..1}--[ IncidentId ]
| ENUM action |<>--{0..1}--[ Contact ]
| STRING ext-action |<>--{0..*}--[ Description ]
| ID observable-id |<>--{0..*}--[ DefinedCOA ]
| |<>--{0..*}--[ AdditionalData ]
+-------------------------+
Figure 27: HistoryItem Class
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The aggregate classes that constitute HistoryItem are:
DateTime
One. Timestamp of this entry in the history log (e.g., when the
action described in the Description was taken).
IncidentID
Zero or One. In a history log created by multiple parties, the
IncidentID provides a mechanism to specify which CSIRT created a
particular entry and references this organization's incident
tracking number. When a single organization is maintaining the
log, this class can be ignored.
Contact
Zero or One. Provides contact information for the person that
performed the action documented in this class.
Description
Zero or more. ML_STRING. A free-form textual description of the
action or event.
DefinedCOA
Zero or more. ML_STRING. A unique identifier meaningful to the
sender and recipient of this document that references a course of
action. This class MUST be present if the action attribute is set
to "defined-coa".
AdditionalData
Zero or more. A mechanism by which to extend the data model.
The HistoryItem class has five attributes:
restriction
Optional. ENUM. See Section 3.3.1.
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
action
Required. ENUM. Classifies a performed action or occurrence
documented in this history log entry. As activity will likely
have been instigated either through a previously conveyed
expectation or internal investigation, this attribute is identical
to the action attribute of the Expectation class. The difference
is only one of tense. When an action is in this class, it has
been completed. See Section 3.17.
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ext-action
Optional. STRING. A means by which to extend the action
attribute. See Section 5.1.1.
observable-id
Optional. ID. See Section 3.3.2.
3.16. EventData Class
The EventData class describes a particular event of the incident for
a given set of hosts or networks. This description includes the
systems from which the activity originated and those targeted, an
assessment of the techniques used by the intruder, the impact of the
activity on the organization, and any forensic evidence discovered.
+-------------------------+
| EventData |
+-------------------------+
| ENUM restriction |<>--{0..*}--[ Description ]
| STRING ext-restriction |<>--{0..1}--[ DetectTime ]
| ID observable-id |<>--{0..1}--[ StartTime ]
| |<>--{0..1}--[ EndTime ]
| |<>--{0..1}--[ RecoveryTime ]
| |<>--{0..1}--[ ReportTime ]
| |<>--{0..*}--[ Contact ]
| |<>--{0..*}--[ Discovery ]
| |<>--{0..1}--[ Assessment ]
| |<>--{0..*}--[ Method ]
| |<>--{0..*}--[ Flow ]
| |<>--{0..*}--[ Expectation ]
| |<>--{0..1}--[ Record ]
| |<>--{0..*}--[ EventData ]
| |<>--{0..*}--[ AdditionalData ]
+-------------------------+
Figure 28: The EventData Class
The aggregate classes that constitute EventData are:
Description
Zero or more. ML_STRING. A free-form textual description of the
event.
DetectTime
Zero or one. The time the event was detected.
StartTime
Zero or one. The time the event started.
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EndTime
Zero or one. The time the event ended.
RecoveryTime
Zero or one. The time the site recovered from the event.
ReportTime
One. The time the event was reported.
Contact
Zero or more. Contact information for the parties involved in the
event.
Discovery
Zero or more. The means by which the event was detected.
Assessment
Zero or one. The impact of the event on the target and the
actions taken.
Method
Zero or more. The technique used by the intruder in the event.
Flow
Zero or more. A description of the systems or networks involved.
Expectation
Zero or more. The expected action to be performed by the
recipient for the described event.
Record
Zero or one. Supportive data (e.g., log files) that provides
additional information about the event.
EventData
Zero or more. EventData instances contained within another
EventData instance inherit the values of the parent(s); this
recursive definition can be used to group common data pertaining
to multiple events. When EventData elements are defined
recursively, only the leaf instances (those EventData instances
not containing other EventData instances) represent actual events.
AdditionalData
Zero or more. An extension mechanism for data not explicitly
represented in the data model.
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At least one of the aggregate classes MUST be present in an instance
of the EventData class. This is not enforced in the IODEF schema as
there is no simple way to accomplish it.
The EventData class has three attributes:
restriction
Optional. ENUM. See Section 3.3.1. The default value is
"default".
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
observable-id
Optional. ID. See Section 3.3.2.
3.16.1. Relating the Incident and EventData Classes
There is substantial overlap in the Incident and EventData classes.
Nevertheless, the semantics of these classes are quite different.
The Incident class provides summary information about the entire
incident, while the EventData class provides information about the
individual events comprising the incident. In the most common case,
the EventData class will provide more specific information for the
general description provided in the Incident class. However, it may
also be possible that the overall summarized information about the
incident conflicts with some individual information in an EventData
class when there is a substantial composition of various events in
the incident. In such a case, the interpretation of the more
specific EventData MUST supersede the more generic information
provided in Incident.
3.16.2. Cardinality of EventData
The EventData class is container for the properties of an event in an
incident. These properties include: the hosts involved, impact of
the incident activity on the hosts, forensic logs, etc. With an
instance of the EventData class, hosts are grouped around these
common properties.
The recursive definition of the EventData class (the EventData class
is aggregated into the EventData class) provides a way to relate
information without requiring the explicit use of unique attribute
identifiers in the classes or duplicating information. Instead, the
relative depth (nesting) of a class is used to group (relate)
information.
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For example, an EventData class might be used to describe two
machines involved in an incident. This description can be achieved
using multiple instances of the Flow class. It happens that there is
a common technical contact (i.e., Contact class) for these two
machines, but the impact (i.e., Assessment class) on them is
different. A depiction of the representation for this situation can
be found in Figure 29.
+------------------+
| EventData |
+------------------+
| |<>----[ Contact ]
| |
| |<>----[ EventData ]<>----[ Flow ]
| | [ ]<>----[ Assessment ]
| |
| |<>----[ EventData ]<>----[ Flow ]
| | [ ]<>----[ Assessment ]
+------------------+
Figure 29: Recursion in the EventData Class
3.17. Expectation Class
The Expectation class conveys to the recipient of the IODEF document
the actions the sender is requesting. The scope of the requested
action is limited to purview of the EventData class in which this
class is aggregated.
+-------------------------+
| Expectation |
+-------------------------+
| ENUM restriction |<>--{0..*}--[ Description ]
| STRING ext-restriction |<>--{0..*}--[ DefinedCOA ]
| ENUM severity |<>--{0..1}--[ StartTime ]
| ENUM action |<>--{0..1}--[ EndTime ]
| STRING ext-action |<>--{0..1}--[ Contact ]
| ID observable-id |
| |
+-------------------------+
Figure 30: The Expectation Class
The aggregate classes that constitute Expectation are:
Description
Zero or more. ML_STRING. A free-form description of the desired
action(s).
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DefinedCOA
Zero or more. ML_STRING. A unique identifier meaningful to the
sender and recipient of this document that references a course of
action. This class MUST be present if the action attribute is set
to "defined-coa".
StartTime
Zero or one. The time at which the sender would like the action
performed. A timestamp that is earlier than the ReportTime
specified in the Incident class denotes that the sender would like
the action performed as soon as possible. The absence of this
element indicates no expectations of when the recipient would like
the action performed.
EndTime
Zero or one. The time by which the sender expects the recipient
to complete the action. If the recipient cannot complete the
action before EndTime, the recipient MUST NOT carry out the
action. Because of transit delays, clock drift, and so on, the
sender MUST be prepared for the recipient to have carried out the
action, even if it completes past EndTime.
Contact
Zero or one. The expected actor for the action.
The Expectations class has six attributes:
restriction
Optional. ENUM. See Section 3.3.1. The default value is
"default".
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
severity
Optional. ENUM. Indicates the desired priority of the action.
This attribute is an enumerated list with no default value, and
the semantics of these relative measures are context dependent.
1. low. Low priority
2. medium. Medium priority
3. high. High priority
action
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Optional. ENUM. Classifies the type of action requested. This
attribute is an enumerated list with a default value of "other".
These values are maintained in the "Expectation-action" IANA
registry per Table 1.
1. nothing. No action is requested. Do nothing with the
information.
2. contact-source-site. Contact the site(s) identified as the
source of the activity.
3. contact-target-site. Contact the site(s) identified as the
target of the activity.
4. contact-sender. Contact the originator of the document.
5. investigate. Investigate the systems(s) listed in the event.
6. block-host. Block traffic from the machine(s) listed as
sources the event.
7. block-network. Block traffic from the network(s) lists as
sources in the event.
8. block-port. Block the port listed as sources in the event.
9. rate-limit-host. Rate-limit the traffic from the machine(s)
listed as sources in the event.
10. rate-limit-network. Rate-limit the traffic from the
network(s) lists as sources in the event.
11. rate-limit-port. Rate-limit the port(s) listed as sources in
the event.
12. redirect-traffic. Redirect traffic from intended recipient
for further analysis.
13. honeypot. Redirect traffic to a honeypot for further
analysis.
14. upgrade-software. Upgrade or patch the software or firmware
on an asset.
15. rebuild-asset. Reinstall the operating system or
applications on an asset.
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16. harden-asset. Change the configuration an asset (e.g.,
reduce the number of services or user accounts) to reduce the
attack surface.
17. remediate-other. Remediate the activity in a way other than
by rate limiting or blocking.
18. status-triage. Conveys receipts and the triaging of an
incident.
19. status-new-info. Conveys that new information was received
for this incident.
20. watch-and-report. Watch for the described activity and share
if seen.
21. training. Train user to identify or mitigate a threat.
22. defined-coa. Perform a predefined course of action (COA).
The COA is named in the DefinedCOA class.
23. other. Perform some custom action described in the
Description class.
24. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-action
Optional. STRING. A means by which to extend the action
attribute. See Section 5.1.1.
observable-id
Optional. ID. See Section 3.3.2.
3.18. Flow Class
The Flow class groups related the source and target hosts.
+------------------+
| Flow |
+------------------+
| |<>--{1..*}--[ System ]
+------------------+
Figure 31: The Flow Class
The aggregate class that constitutes Flow is:
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System
One or More. A host or network involved in an event.
The Flow class has no attributes.
3.19. System Class
The System class describes a system or network involved in an event.
The systems or networks represented by this class are categorized
according to the role they played in the incident through the
category attribute. The value of this category attribute dictates
the semantics of the aggregated classes in the System class. If the
category attribute has a value of "source", then the aggregated
classes denote the machine and service from which the activity is
originating. With a category attribute value of "target" or
"intermediary", then the machine or service is the one targeted in
the activity. A value of "sensor" dictates that this System was part
of an instrumentation to monitor the network.
+------------------------+
| System |
+------------------------+
| ENUM restriction |<>----------[ Node ]
| STRING ext-restriction |<>--{0..*}--[ NodeRole ]
| ENUM category |<>--{0..*}--[ Service ]
| STRING ext-category |<>--{0..*}--[ OperatingSystem ]
| STRING interface |<>--{0..*}--[ Counter ]
| ENUM spoofed |<>--{0..*}--[ AssetID ]
| ENUM virtual |<>--{0..*}--[ Description ]
| ENUM ownership |<>--{0..*}--[ AdditionalData ]
| STRING ext-ownership |
| |
+------------------------+
Figure 32: The System Class
The aggregate classes that constitute System are:
Node
One. A host or network involved in the incident.
NodeRole
Zero or more. The intended purpose of the system.
Service
Zero or more. A network service running on the system.
OperatingSystem
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Zero or more. The operating system running on the system.
Counter
Zero or more. A counter with which to summarize properties of
this host or network.
AssetID
Zero or more. An asset identifier for the System.
Description
Zero or more. ML_STRING. A free-form text description of the
System.
AdditionalData
Zero or more. A mechanism by which to extend the data model.
The System class has nine attributes:
restriction
Optional. ENUM. See Section 3.3.1.
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
category
Optional. ENUM. Classifies the role the host or network played
in the incident. These values are maintained in the "System-
category" IANA registry per Table 1. The possible values are:
1. source. The System was the source of the event.
2. target. The System was the target of the event.
3. intermediate. The System was an intermediary in the event.
4. sensor. The System was a sensor monitoring the event.
5. infrastructure. The System was an infrastructure node of
IODEF document exchange.
6. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-category
Optional. STRING. A means by which to extend the category
attribute. See Section 5.1.1.
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interface
Optional. STRING. Specifies the interface on which the event(s)
on this System originated. If the Node class specifies a network
rather than a host, this attribute has no meaning.
spoofed
Optional. ENUM. An indication of confidence in whether this
System was the true target or attacking host. The permitted
values for this attribute are shown below. The default value is
"unknown".
1. unknown. The accuracy of the category attribute value is
unknown.
2. yes. The category attribute value is probably incorrect. In
the case of a source, the System is likely a decoy; with a
target, the System was likely not the intended victim.
3. no. The category attribute value is believed to be correct.
virtual
Optional. ENUM. Indicates whether this System is a virtual or
physical device. The default value is "unknown". The possible
values are:
1. yes. The System is a virtual device.
2. no. The System is a physical device.
3. unknown. It is not known if the System is virtual.
ownership
Optional. ENUM. Describes the ownership of this System relative
to the sender of the IODEF document. These values are maintained
in the "System-ownership" IANA registry per Table 1. The possible
values are:
1. organization. The System is owned by the organization.
2. personal. The System is owned by employee or affiliate of the
organization.
3. partner. The System is owned by a partner of the
organization.
4. customer. The System is owned by a customer of the
organization.
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5. no-relationship. The System is owned by an entity that has no
known relationship with the organization.
6. unknown. The ownership of the System is unknown.
7. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-ownership
Optional. STRING. A means by which to extend the ownership
attribute. See Section 5.1.1.
3.20. Node Class
The Node class names an asset or network.
This class was derived from [RFC4765].
+---------------+
| Node |
+---------------+
| |<>--{0..*}--[ DomainData ]
| |<>--{0..*}--[ Address ]
| |<>--{0..1}--[ PostalAddress ]
| |<>--{0..*}--[ Location ]
| |<>--{0..1}--[ DateTime ]
| |<>--{0..*}--[ Counter ]
+---------------+
Figure 33: The Node Class
The aggregate classes that constitute Node are:
DomainData
Zero or more. The detailed domain (DNS) information associated
with this Node. If an Address is not provided, at least one
DomainData MUST be specified.
Address
Zero or more. The hardware, network, or application address of
the Node. If a DomainData is not provided, at least one Address
MUST be specified.
PostalAddress
Zero or one. The postal address of the asset.
Location
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Zero or more. ML_STRING. A free-form description of the physical
location of the Node. This description may provide a more
detailed description of where in the PostalAddress this Node is
found (e.g., room number, rack number, slot number in a chassis).
Counter
Zero or more. A counter with which to summarizes properties of
this host or network.
The Node class has no attributes.
3.20.1. Address Class
The Address class represents a hardware (layer-2), network (layer-3),
or application (layer-7) address.
This class was derived from [RFC4765].
+-------------------------+
| Address |
+-------------------------+
| ENUM category |
| STRING ext-category |
| STRING vlan-name |
| INTEGER vlan-num |
| ID observable-id |
+-------------------------+
Figure 34: The Address Class
The Address class has five attributes:
category
Optional. ENUM. The type of address represented. The permitted
values for this attribute are shown below. The default value is
"ipv4-addr". These values are maintained in the "Address-
category" IANA registry per Table 1.
1. asn. Autonomous System Number
2. atm. Asynchronous Transfer Mode (ATM) address
3. e-mail. Electronic mail address (RFC 822)
4. ipv4-addr. IPv4 host address in dotted-decimal notation
(a.b.c.d)
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5. ipv4-net. IPv4 network address in dotted-decimal notation,
slash, significant bits (i.e., a.b.c.d/nn)
6. ipv4-net-mask. IPv4 network address in dotted-decimal
notation, slash, network mask in dotted-decimal notation
(i.e., a.b.c.d/w.x.y.z)
7. ipv6-addr. IPv6 host address
8. ipv6-net. IPv6 network address, slash, significant bits
9. ipv6-net-mask. IPv6 network address, slash, network mask
10. mac. Media Access Control (MAC) address (i.e., a:b:c:d:e:f)
11. site-uri. A URL or URI for a resource.
12. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-category
Optional. STRING. A means by which to extend the category
attribute. See Section 5.1.1.
vlan-name
Optional. STRING. The name of the Virtual LAN to which the
address belongs.
vlan-num
Optional. STRING. The number of the Virtual LAN to which the
address belongs.
observable-id
Optional. ID. See Section 3.3.2.
3.20.2. NodeRole Class
The NodeRole class describes the function performed by a particular .
+---------------------+
| NodeRole |
+---------------------+
| ENUM category |
| STRING ext-category |
| ENUM xml:lang |
+---------------------+
Figure 35: The NodeRole Class
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The NodeRole class has three attributes:
category
Required. ENUM. Functionality provided by a node. These values
are maintained in the "NodeRole-category" IANA registry per
Table 1.
1. client. Client computer
2. client-enterprise. Client computer on the enterprise network
3. client-partner. Client computer on network of a partner
4. client-remote. Client computer remotely connected to the
enterprise network
5. client-kiosk. Client computer is serves as a kiosk
6. client-mobile. Client is a mobile device
7. server-internal. Server with internal services
8. server-public. Server with public services
9. www. WWW server
10. mail. Mail server
11. webmail. Web mail server
12. messaging. Messaging server (e.g., NNTP, IRC, IM)
13. streaming. Streaming-media server
14. voice. Voice server (e.g., SIP, H.323)
15. file. File server (e.g., SMB, CVS, AFS)
16. ftp. FTP server
17. p2p. Peer-to-peer node
18. name. Name server (e.g., DNS, WINS)
19. directory. Directory server (e.g., LDAP, finger, whois)
20. credential. Credential server (e.g., domain controller,
Kerberos)
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21. print. Print server
22. application. Application server
23. database. Database server
24. backup. Backup server
25. dhcp. DHCP server
26. assessment. Assessment server (e.g., vulnerability scanner,
end-point assessment)
27. source-control. Source code control server
28. config-management. Configuration management server
29. monitoring. Security monitoring server (e.g., IDS)
30. infra. Infrastructure server (e.g., router, firewall, DHCP)
31. infra-firewall. Firewall
32. infra-router. Router
33. infra-switch. Switch
34. camera. Camera and video system
35. proxy. Proxy server
36. remote-access. Remote access server
37. log. Log server (e.g., syslog)
38. virtualization. Server running virtual machines
39. pos. Point-of-sale device
40. scada. Supervisory control and data acquisition system
41. scada-supervisory. Supervisory system for a SCADA
42. sinkhole. Traffic sinkhole destination
43. honeypot. Honeypot server
44. anonymization. Anonymization server (e.g., Tor node)
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45. c2. Malicious command and control server
46. malware-distribution. Server that distributes malware
47. drop-server. Server to which exfiltrated content is
uploaded.
48. hop-point. Intermediary server used to get to a victim.
49. reflector. A system used in a reflector attacker.
50. phishing-site. Site hosting phishing content
51. spear-phishing-site. Site hosting spear-phishing content
52. recruiting-site. Site to recruit
53. fraudulent-site. Fraudulent site.
54. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-category
Optional. STRING. A means by which to extend the category
attribute. See Section 5.1.1.
xml:lang
Optional. ENUM. A language identifier per Section 2.12 of
[W3C.XML] whose values and form are described in [RFC5646]. The
interpretation of this code is described in Section 6.
3.20.3. Counter Class
The Counter class summarize multiple occurrences of some event, or
conveys counts or rates on various features (e.g., packets, sessions,
events).
The value of the counter is the element content with its units
represented in the type attribute. A rate for a given feature can be
expressed by setting the duration attribute. The complete semantics
are entirely context dependent based on the class in which the
Counter is aggregated.
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+---------------------+
| Counter |
+---------------------+
| REAL |
| |
| ENUM type |
| STRING ext-type |
| ENUM unit |
| STRING ext-unit |
| STRING meaning |
| ENUM duration |
| STRING ext-duration |
+---------------------+
Figure 36: The Counter Class
The Counter class has seven attribute:
type
Required. ENUM. Specifies the type of counter specified in the
element content. These values are maintained in the "Counter-
type" IANA registry per Table 1.
1. count. The Counter class value is a counter.
2. peak. The Counter class value is a peak value.
3. average. The Counter class value is an average.
4. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-type
Optional. STRING. A means by which to extend the type attribute.
See Section 5.1.1.
unit
Required. ENUM. Specifies the units of the element content.
These values are maintained in the "Counter-unit" IANA registry
per Table 1.
1. byte. Bytes transferred.
2. mbit. Megabits (Mbits) transfered.
3. packet. Packets.
4. flow. Network flow records.
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5. session. Sessions.
6. alert. Notifications generated by another system (e.g., IDS
or SIM).
7. message. Messages (e.g., mail messages).
8. event. Events.
9. host. Hosts.
10. site. Site.
11. organization. Organizations.
12. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-unit
Optional. STRING. A means by which to extend the unit attribute.
See Section 5.1.1.
meaning
Optional. STRING. A free-form description of the metric
represented by the Counter.
duration
Optional. ENUM. If present, the Counter class represents a rate.
This attribute specifies unit of time over which the rate whose
units are specified in the unit attribute is being conveyed. This
attribute is the the denominator of the rate (where the unit
attribute specified the nominator). The possible values of this
attribute are defined in Section 3.14.3
ext-duration
Optional. STRING. A means by which to extend the duration
attribute. See Section 5.1.1.
3.21. DomainData Class
The DomainData class describes a domain name and meta-data associated
with this domain.
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+--------------------------+
| DomainData |
+--------------------------+
| ENUM system-status |<>----------[ Name ]
| STRING ext-system-status |<>--{0..1}--[ DateDomainWasChecked ]
| ENUM domain-status |<>--{0..1}--[ RegistrationDate ]
| STRING ext-domain-status |<>--{0..1}--[ ExpirationDate ]
| ID observable-id |<>--{0..*}--[ RelatedDNS ]
| |<>--{0..*}--[ Nameservers ]
| |<>--{0..1}--[ DomainContacts ]
| |
+--------------------------+
Figure 37: The DomainData Class
The aggregate classes that constitute DomainData are:
Name
One. STRING. The domain name of the Node (e.g., fully qualified
domain name).
DateDomainWasChecked
Zero or one. DATETIME. A timestamp of when the Name was
resolved.
RegistrationDate
Zero or one. DATETIME. A timestamp of when domain listed in Name
was registered.
ExpirationDate
Zero or one. DATETIME. A timestamp of when the domain listed in
Name is set to expire.
RelatedDNS
Zero or more. Additional DNS records associated with this domain.
Nameservers
Zero or more. The name servers identified for the domain listed
in Name.
DomainContacts
Zero or one. Contact information for the domain listed in Name
supplied by the registrar or through a whois query.
The DomainData class has five attribute:
system-status
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Required. ENUM. Assesses the domain's involvement in the event.
These values are maintained in the "DomainData-system-status" IANA
registry per Table 1.
1. spoofed. This domain was spoofed.
2. fraudulent. This domain was operated with fraudulent
intentions.
3. innocent-hacked. This domain was compromised by a third
party.
4. innocent-hijacked. This domain was deliberately hijacked.
5. unknown. No categorization for this domain known.
6. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-system-status
Optional. STRING. A means by which to extend the system-status
attribute. See Section 5.1.1.
domain-status
Required. ENUM. Categorizes the registry status of the domain at
the time the document was generated. These values and their
associated descriptions are derived from Section 3.2.2 of
[RFC3982]. These values are maintained in the "DomainData-domain-
status" IANA registry per Table 1.
1. reservedDelegation. The domain is permanently inactive.
2. assignedAndActive. The domain is in a normal state.
3. assignedAndInactive. The domain has an assigned registration
but the delegation is inactive.
4. assignedAndOnHold. The domain is under dispute.
5. revoked. The domain is in the process of being purged from
the database.
6. transferPending. The domain is pending a change in
authority.
7. registryLock. The domain is on hold by the registry.
8. registrarLock. Same as "registryLock".
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9. other. The domain has a known status but it is not one of
the redefined enumerated values.
10. unknown. The domain has an unknown status.
11. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-domain-status
Optional. STRING. A means by which to extend the domain-status
attribute. See Section 5.1.1.
observable-id
Optional. ID. See Section 3.3.2.
3.21.1. RelatedDNS
The RelatedDNS class describes additional record types associated
with a given domain name. The record type is described in the
record-type attribute and the value of the record is the element
content. ... TODO Issue #39 ...
+----------------------+
| RelatedDNS |
+----------------------+
| STRING |
| |
| ENUM record-type |
+----------------------+
Figure 38: The RelatedDNS Class
The RelatedDNS class has one attribute:
record-type
Required. ENUM. The DNS record type. ... TODO values need to be
listed ...
3.21.2. Nameservers Class
The Nameservers class describes the name servers associated with a
given domain.
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+--------------------+
| Nameservers |
+--------------------+
| |<>----------[ Server ]
| |<>--{1..*}--[ Address ]
+--------------------+
Figure 39: The Nameservers Class
The aggregate classes that constitute Nameservers are:
Server
One. STRING. The domain name of the name server.
Address
One or more. The address of the name server. See Section 3.20.1.
3.21.3. DomainContacts Class
The DomainContacts class describes the contact information for a
given domain provided either by the registrar or through a whois
query.
This contact information can be explicitly described through a
Contact class or a reference can be provided to a domain with
identical contact information. Either a single SameDomainContact
MUST be present or one or many Contact classes.
+--------------------+
| DomainContacts |
+--------------------+
| |<>--{0..1}--[ SameDomainContact ]
| |<>--{1..*}--[ Contact ]
+--------------------+
Figure 40: The DomainContacts Class
The aggregate classes that constitute DomainContacts are:
SameDomainContact
Zero or one. STRING. A domain name already cited in this
document or through previous exchange that contains the identical
contact information as the domain name in question. The domain
contact information associated with this domain should be used
instead of an explicit definition with the Contact class.
Contact
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One or more. Contact information for the domain. See
Section 3.10.
3.22. Service Class
The Service class describes a network service of a host or network.
The service is identified by specific port or list of ports, along
with the application listening on that port.
When Service occurs as an aggregate class of a System that is a
source, then this service is the one from which activity of interest
is originating. Conversely, when Service occurs as an aggregate
class of a System that is a target, then that service is the one to
which activity of interest is directed.
This class was derived from [RFC4765].
+-------------------------+
| Service |
+-------------------------+
| INTEGER ip-protocol |<>--{0..1}--[ ServiceName ]
| ID observable-id |<>--{0..1}--[ Port ]
| |<>--{0..1}--[ Portlist ]
| |<>--{0..1}--[ ProtoCode ]
| |<>--{0..1}--[ ProtoType ]
| |<>--{0..1}--[ ProtoField ]
| |<>--{0..*}--[ ApplicationHeader ]
| |<>--{0..1}--[ EmailData ]
| |<>--{0..1}--[ Application ]
+-------------------------+
Figure 41: The Service Class
The aggregate classes that constitute Service are:
ServiceName
Zero or one. Identifies the the observed service.
Port
Zero or one. INTEGER. A port number.
Portlist
Zero or one. PORTLIST. A list of port numbers formatted
according to Section 2.10.
ProtoCode
Zero or one. INTEGER. A transport layer (layer 4) protocol-
specific code field (e.g., ICMP code field).
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ProtoType
Zero or one. INTEGER. A transport layer (layer 4) protocol
specific type field (e.g., ICMP type field).
ProtoField
Zero or one. INTEGER. A transport layer (layer 4) protocol
specific flag field (e.g., TCP flag field).
ApplicationHeader
Zero or more. An application layer (layer 7) protocol header.
See Section 3.22.2.
EmailData
Zero or one. Headers associated with an email. See Section 3.24.
Application
Zero or one. The application bound to the specified Port or
Portlist. See Section 3.22.3.
Either a Port or Portlist class MUST be specified for a given
instance of a Service class.
When a given System classes with category="source" and another with
category="target" are aggregated into a single Flow class, and each
of these System classes has a Service and Portlist class, an implicit
relationship between these Portlists exists. If N ports are listed
for a System@category="source", and M ports are listed for
System@category="target", the number of ports in N must be equal to
M. Likewise, the ports MUST be listed in an identical sequence such
that the n-th port in the source corresponds to the n-th port of the
target. If N is greater than 1, a given instance of a Flow class
MUST only have a single instance of a System@category="source" and
System@category="target".
The Service class has two attributes:
ip-protocol
Required. INTEGER. The IANA assigned IP protocol number per
[IANA.Protocols].
observable-id
Optional. ID. See Section 3.3.2.
3.22.1. ServiceName Class
The ServiceName class names an application protocol. It can be
described by referencing an IANA registered protocol, a URL or with
free-form text.
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+--------------------+
| ServiceName |
+--------------------+
| |<>--{0..1}--[ IANAService ]
| |<>--{0..*}--[ URL ]
| |<>--{0..*}--[ Description ]
+--------------------+
Figure 42: The ServiceName Class
The aggregate classes that constitute ServiceName:
IANAService
Zero or one. The name of the service per the "Service Name" field
of the [IANA.Ports] registry.
URL
Zero or more. URL. A URL describing the service.
Description
Zero or more. ML_STRING. A free-form text description of the
service.
At least one of these classes MUST be present.
The ServiceName class has no attributes.
3.22.2. ApplicationHeader Class
The ApplicationHeader class allows the representation of arbitrary
fields from an application layer protocol header and its
corresponding value.
+--------------------------+
| ApplicationHeader |
+--------------------------+
| ANY |
| |
| INTEGER proto |
| STRING proto-name |
| STRING field |
| ENUM dtype |
| STRING ext-dtype |
| ID observable-id |
+--------------------------+
Figure 43: The ApplicationHeader Class
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The ApplicationHeader class has six attributes:
proto
Optional. INTEGER. The IANA assigned port number per the
"Protocol Number" field of the [IANA.Ports] registry corresponding
to the application layer protocol whose field will be represented.
proto-name
Optional. STRING. The IANA assigned service name per the
"Service Name" field of the the [IANA.Ports] registry
corresponding to the application layer protocol whose field will
be represented.
field
Required. STRING. The name of the protocol field whose value
will be found in the element body.
dtype
Required. ENUM. The data type of the element content. The
permitted values for this attribute are shown below. The default
value is "string". These values are maintained in the
"ApplicationHeader-proto-dtype" IANA registry per Table 1.
1. boolean. The element content is of type BOOLEAN.
2. byte. The element content is of type BYTE.
3. bytes. The element content is of type HEXBIN.
4. character. The element content is of type CHARACTER.
5. date-time. The element content is of type DATETIME.
6. integer. The element content is of type INTEGER.
7. portlist. The element content is of type PORTLIST.
8. real. The element content is of type REAL.
9. string. The element content is of type STRING.
10. file. The element content is a base64 encoded binary file
encoded as a BYTE[] type.
11. path. The element content is a file-system path encoded as a
STRING type.
12. xml. The element content is XML. See Section 5.
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13. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-dtype
Optional. STRING. A means by which to extend the dtype
attribute. See Section 5.1.1.
observable-id
Optional. ID. See Section 3.3.2.
Either the proto or proto-name attribute MUST be set. If both are
set, they MUST correspond to the same entry in the registry.
3.22.3. Application Class
The Application class describes a software application. It can be
described by using formal reference, a URL or with free-form text.
+--------------------+
| Application |
+--------------------+
| |<>--{0..1}--[ SoftwareReference ]
| |<>--{0..*}--[ URL ]
| |<>--{0..*}--[ Description ]
+--------------------+
Figure 44: The Application Class
The aggregate classes that constitute Application:
SoftwareReference
Zero or one. Reference to a software application.
URL
Zero or more. URL. A URL associated with the application.
Description
Zero or more. ML_STRING. A free-form text description of this
application.
At least one of these classes MUST be present.
The Application class has no attributes.
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3.22.4. SoftwareReference Class
The Application class describes a software application. It can be
described by using formal reference, a URL or with free-form text.
+----------------------+
| SoftwareReference |
+----------------------+
| ANY |
| |
| ENUM spec-name |
| STRING ext-spec-name |
| ENUM dtype |
| STRING enum-dtype |
+----------------------+
Figure 45: The SoftwareReference Class
The element body of this class varies according to the value of the
spec-name attribute.
The SoftwareReference class has four attributes:
spec-name
Required. ENUM. Identifies the format and semantics of the
element body of this class. Formal standards and specifications
can be referenced as well as free-form description with user-
provided data-types. These values are maintained in the
"SoftwareReference-spec-id" IANA registry per Table 1
1. custom. The element content is free-form and of the data type
specified by the dtype attribute. If this value is selected,
then the dtype attribute MUST be set.
2. cpe. The element content describes a Common Platform
Enumeration (CPE) entry [fix me. reference].
3. swid. The element content describes a software identification
(SWID) tag per ISO/IEC 19770-2:2009 [fix me. reference].
4. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-spec-name
Optional. STRING. A means by which to extend the spec-name
attribute. See Section 5.1.1.
dtype
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Optional. ENUM. The data type of the element content. The
permitted values for this attribute are shown below. The default
value is "string". These values are maintained in the
"SoftwareReference-dtype" IANA registry per Table 1.
1. bytes. The element content is of type HEXBIN.
2. integer. The element content is of type INTEGER.
3. real. The element content is of type REAL.
4. string. The element content is of type STRING.
5. xml. The element content is XML. See Section 5.
6. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-dtype
Optional. STRING. A means by which to extend the dtype
attribute. See Section 5.1.1.
3.23. OperatingSystem Class
The OperatingSystem class describes the operating system running on a
System. The definition is identical to the Application class
(Section 3.22.3).
3.24. EmailData Class
The EmailData class describes headers from an email message. Common
headers have dedicated classes, but arbitrary headers can also be
described.
+-------------------------+
| EmailData |
+-------------------------+
| ID observable-id |<>--{0..1}--[ EmailFrom ]
| |<>--{0..1}--[ EmailSubject ]
| |<>--{0..1}--[ EmailX-Mailer ]
| |<>--{0..*}--[ EmailHeaderField ]
| |<>--{0..*}--[ HashData ]
| |<>--{0..*}--[ SignatureData ]
+-------------------------+
Figure 46: EmailData Class
The aggregate class that constitutes EmailData are:
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EmailFrom
Zero or one. The value of the "From:" header field in an email.
See Section 3.6.2 of [RFC5322].
EmailSubject
Zero or one. The value of the "Subject:" header field in an
email. See Section 3.6.4 of [RFC5322].
EmailX-Mailer
Zero or one. The value of the "X-Mailer:" header field in an
email.
EmailHeaderField
Zero or one. The value of an arbitrary header field in the email.
See Section 3.22.2. The attributes of EmailHeaderField MUST be
set as follows: proto="25" or proto-name="smtp", or both can be
set; and dtype="string". The name of the email header field MUST
be set in the field attribute.
HashData
Zero or One. Hash(es) associated with this email.
SignatureData
Zero or One. Signature(s) associated with this email.
The EmailData class has one attribute:
observable-id
Optional. ID. See Section 3.3.2.
3.25. Record Class
The Record class is a container class for log and audit data that
provides supportive information about the incident. The source of
this data will often be the output of monitoring tools. These logs
substantiate the activity described in the document.
+------------------------+
| Record |
+------------------------+
| ENUM restriction |<>--{1..*}--[ RecordData ]
| STRING ext-restriction |
+------------------------+
Figure 47: Record Class
The aggregate class that constitutes Record is:
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RecordData
One or more. Log or audit data generated by a particular type of
sensor. Separate instances of the RecordData class SHOULD be used
for each sensor type.
The Record class has two attributes:
restriction
Optional. ENUM. See Section 3.3.1.
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
3.25.1. RecordData Class
The RecordData class groups log or audit data from a given sensor
(e.g., IDS, firewall log) and provides a way to annotate the output.
+------------------------+
| RecordData |
+------------------------+
| ENUM restriction |<>--{0..1}--[ DateTime ]
| STRING ext-restriction |<>--{0..*}--[ Description ]
| ID observable-id |<>--{0..1}--[ Application ]
| |<>--{0..*}--[ RecordPattern ]
| |<>--{0..*}--[ RecordItem ]
| |<>--{0..*}--[ FileData ]
| |<>--{0..*}--[ CertificateData ]
| |<>--{0..*}--
| | [ WindowsRegistryKeysModified ]
| |<>--{0..*}--[ AdditionalData ]
+------------------------+
Figure 48: The RecordData Class
The aggregate classes that constitutes RecordData is:
DateTime
Zero or one. Timestamp of the RecordItem data.
Description
Zero or more. ML_STRING. Free-form textual description of the
provided RecordItem data. At minimum, this description should
convey the significance of the provided RecordItem data.
Application
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Zero or one. Information about the sensor used to generate the
RecordItem data.
RecordPattern
Zero or more. A search string to precisely find the relevant data
in a RecordItem.
RecordItem
Zero or more. Log, audit, or forensic data.
FileData
Zero or one. The file name and hash of a file indicator.
WindowsRegistryKeysModified
Zero or more. The registry keys that were modified that are
indicator(s).
AdditionalData
Zero or more. An extension mechanism for data not explicitly
represented in the data model.
The RecordData class has three attributes:
restriction
Optional. ENUM. See Section 3.3.1.
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
observable-id
Optional. ID. See Section 3.3.2.
3.25.2. RecordPattern Class
The RecordPattern class describes where in the content of the
RecordItem relevant information can be found. It provides a way to
reference subsets of information, identified by a pattern, in a large
log file, audit trail, or forensic data.
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+-----------------------+
| RecordPattern |
+-----------------------+
| STRING |
| |
| ENUM type |
| STRING ext-type |
| INTEGER offset |
| ENUM offsetunit |
| STRING ext-offsetunit |
| INTEGER instance |
+-----------------------+
Figure 49: The RecordPattern Class
The specific pattern to search with in the RecordItem is defined in
the body of the element. It is further annotated by six attributes:
type
Required. ENUM. Describes the type of pattern being specified in
the element content. The default is "regex". These values are
maintained in the "RecordPattern-type" IANA registry per Table 1.
1. regex. regular expression as defined by POSIX Extended
Regular Expressions (ERE) in Chapter 9 of [IEEE.POSIX].
2. binary. Binhex encoded binary pattern, per the HEXBIN data
type.
3. xpath. XML Path (XPath) [W3C.XPATH]
4. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-type
Optional. STRING. A means by which to extend the type attribute.
See Section 5.1.1.
offset
Optional. INTEGER. Amount of units (determined by the offsetunit
attribute) to seek into the RecordItem data before matching the
pattern.
offsetunit
Optional. ENUM. Describes the units of the offset attribute.
The default is "line". These values are maintained in the
"RecordPattern-offsetunit" IANA registry per Table 1.
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1. line. Offset is a count of lines.
2. byte. Offset is a count of bytes.
3. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-offsetunit
Optional. STRING. A means by which to extend the offsetunit
attribute. See Section 5.1.1.
instance
Optional. INTEGER. Number of types to apply the specified
pattern.
3.25.3. RecordItem Class
The RecordItem class provides a way to incorporate relevant logs,
audit trails, or forensic data to support the conclusions made during
the course of analyzing the incident. The class supports both the
direct encapsulation of the data, as well as, provides primitives to
reference data stored elsewhere.
This class is identical to AdditionalData class (Section 3.9).
3.26. WindowsRegistryKeysModified Class
The WindowsRegistryKeysModified class describes Windows operating
system registry keys and the operations that were performed on them.
This class was derived from [RFC5901].
+-----------------------------+
| WindowsRegistryKeysModified |
+-----------------------------+
| ID observable-id |<>--{1..*}--[ Key ]
+-----------------------------+
Figure 50: The WindowsRegistryKeysModified Class
The aggregate class that constitutes the WindowsRegistryKeysModified
class is:
Key
One or many. The Window registry key.
The WindowsRegistryKeysModified class has one attribute:
observable-id
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Optional. ID. See Section 3.3.2.
3.26.1. Key Class
The Key class describes a particular Windows operating system
registry key name and value pair, and the operation performed on it.
+---------------------------+
| Key |
+---------------------------+
| ENUM registryaction |<>----------[ KeyName ]
| STRING ext-registryaction |<>--{0..1}--[ KeyValue ]
| ID observable-id |
+---------------------------+
Figure 51: The Key Class
The aggregate classes that constitutes Key are:
KeyName
One. STRING. The name of the Windows operating system registry
key (e.g.,[HKEY_LOCAL_MACHINE\Software\Test\KeyName])
KeyValue
Zero or one. STRING. The value of the associated registry key
encoded as in Microsoft .reg files [KB310516].
The Key class has three attributes:
registryaction
Optional. ENUM. The type of action taken on the registry key.
These values are maintained in the "Key-registryaction" IANA
registry per Table 1.
1. add-key. Registry key added.
2. add-value. Value added to registry key.
3. delete-key. Registry key deleted.
4. delete-value. Value deleted from registry key.
5. modify-key. Registry key modified.
6. modify-value. Value modified for registry key.
7. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
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ext-registryaction
Optional. STRING. A means by which to extend the registryaction
attribute. See Section 5.1.1.
observable-id
Optional. ID. See Section 3.3.2.
3.27. CertificateData Class
The CertificateData class describes X.509 certificates.
+------------------------+
| CertificateData |
+------------------------+
| ID observable-id |<>--{1..*}--[ Certificate ]
| ENUM restriction |
| STRING ext-restriction |
+------------------------+
Figure 52: The CertificateData Class
The aggregate classes that constitutes CertificateData are:
Certificate
One or more. A certificate.
The CertificateData class has three attributes:
observable-id
Optional. ID. See Section 3.3.2.
restriction
Optional. ENUM. See Section 3.3.1.
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
3.27.1. Certificate Class
The Certificate class describes a given X.509 certificate or
certificate chain.
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+--------------------------+
| Certificate |
+--------------------------+
| ID observable-id |<>----------[ ds: X509Data ]
| |<>--{0..*}--[ Description ]
+--------------------------+
Figure 53: The Certificate Class
The aggregate classes that constitutes Certificate are:
ds:X509Data
One. A given X.509 certificate or chain. See Section 4.4.4 of
[W3C.XMLSIG].
Description
Zero or more. ML_STRING. Free-form textual description
explaining the context of this certificate.
The Certificate class has one attribute:
observable-id
Optional. ID. See Section 3.3.2.
3.28. FileData Class
The FileData class describes files of interest identified during the
analysis of an incident.
+------------------------+
| FileData |
+------------------------+
| ID observable-id |<>--{1..*}--[ File ]
| ENUM restriction |
| STRING ext-restriction |
+------------------------+
Figure 54: The FileData Class
The aggregate class that constitutes FileData is:
File
One or more. A description of a file.
The FileData class has three attributes:
observable-id
Optional. ID. See Section 3.3.2.
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restriction
Optional. ENUM. See Section 3.3.1.
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
3.28.1. File Class
The File class describes a file and its associated meta data.
+-----------------------+
| File |
+-----------------------+
| ID observable-id |<>--{0..1}--[ FileName ]
| |<>--{0..1}--[ FileSize ]
| |<>--{0..1}--[ FileType ]
| |<>--{0..*}--[ URL ]
| |<>--{0..1}--[ HashData ]
| |<>--{0..1}--[ SignatureData ]
| |<>--{0..1}--[ AssociatedSoftware ]
| |<>--{0..*}--[ FileProperties ]
+-----------------------+
Figure 55: The File Class
The aggregate classes that constitutes File are:
FileName
Zero or One. STRING. The name of the file.
FileSize
Zero or One. INTEGER. The size of the file in bytes.
FileType
Zero or One. STRING. The type of file per the IANA Media Types
Registry [IANA.Media]. Valid values correspond to the text in the
"Template" column (e.g., "application/pdf").
URL
Zero or more. A URL reference to the file.
HashData
Zero or One. Hash(es) associated with this file.
SignatureData
Zero or One. Signature(s) associated with this file.
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AssociatedSoftware
Zero or One. The software application or operating system to
which this file belongs. See Section 3.22.3 for the definition.
FileProperties
Zero or more. Mechanism by which to extend the data model to
describe properties of the file. See Section 3.9.
The File class has one attribute:
observable-id
Optional. ID. See Section 3.3.2.
3.29. HashData Class
The HashData class describes different types of hashes on an given
object (e.g., file, part of a file, email).
+--------------------------+
| HashData |
+--------------------------+
| ENUM scope |<>--{0..1}--[ HashTarget ]
| |<>--{0..*}--[ Hash ]
| |<>--{0..*}--[ FuzzyHash ]
+--------------------------+
Figure 56: The HashData Class
The aggregate classes that constitutes HashData are:
HashTarget
Zero or One. An identifier that references a a subset of the
object per the @scope attribute.
Hash
Zero or more. The hash generated on the object.
FuzzyHash
Zero or more. The fuzzy hash of the object.
A single instance of Hash or FuzzyHash MUST be present.
The HashData class has one attribute:
scope
Required. ENUM. Describes the scope of the hash on a type of
object. These values are maintained in the "HashData-scope" IANA
registry per Table 1.
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1. file-contents. A hash computed over the entire contents of a
file.
2. file-pe-section. A hash computed on a given section of a
Windows Portable Executable (PE) file. If set to this value,
the HashTargetId class MUST identify the section being hashed.
This section is identified by an ordinal number (starting at
1) corresponding to the the order in which the given section
header was defined in the Section Table of the PE file header.
3. file-pe-iat. A hash computed on the Import Address
Table (IAT) of a PE file. As IAT hashes are often tool
dependent, if this value is set, the HashTargetId class MUST
specify the tool used to generate the hash.
4. file-pe-resource. A hash computed on a given resource in a PE
file. If set to this value, the HashTargetId class MUST
identify the resource being hashed. This resource is
identified by an ordinal number (starting at 1) corresponding
to the oder in which the given resource is declared in the
Resource Directory of the Data Dictionary in the PE file
header.
5. file-pdf-object. A hash computed on a given object in a
Portable Document Format (PDF) file. If set to this value,
the HashTargetId class MUST identify the object being hashed.
This object is identified by its offset in the PDF file.
6. email-hash. A hash computed over the headers and body of an
email message.
7. email-headers-hash. A hash computed over all of the headers
of an email message.
8. email-body-hash. A hash computed over the body of an email
message.
9. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-scope
Optional. STRING. A means by which to extend the scope
attribute. See Section 5.1.1.
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3.29.1. Hash Class
The Hash class describes a specific hash value, algorithm, and an
application used to generate it.
+----------------+
| Hash |
+----------------+
| |<>----------[ ds:DigestMethod ]
| |<>----------[ ds:DigestValue ]
| |<>--{0..1}--[ ds:CannonicalizationMethod ]
| |<>--{0..1}--[ Application ]
+----------------+
Figure 57: The Hash Class
The aggregate classes that constitutes Hash are:
ds:DigestMethod
One. The hash algorithm used to generate the hash. See
Section 4.3.3.5 of [W3C.XMLSIG]
ds:DigestValue
One. The computed hash value. See Section 4.3.3.6 of
[W3C.XMLSIG].
ds:CannonicalizationMethod
Zero or one. The canonicalization method used for the has. See
Section 4.3.1 of [W3C.XMLSIG].
Application
Zero or One. The application used to calculate the hash.
The HashData class has no attribute:
3.29.2. FuzzyHash Class
The FuzzyHash class describes a fuzzy hash (in an extensible way) and
the application used to generate it.
+--------------------------+
| FuzzyHash |
+--------------------------+
| |<>--{0..*}--[ AdditionalData ]
| |<>--{0..1}--[ Application ]
+--------------------------+
Figure 58: The FuzzyHash Class
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The aggregate classes that constitutes FuzzyHash are:
AdditionalData
Zero or more. Mechanism by which to extend the data model. See
Section 3.9.
Application
Zero or One. The application used to calculate the hash.
The FuzzyData class has no attribute:
3.30. SignatureData Class
The SignatureData class describes different signatures on an given
object.
+--------------------------+
| SignatureData |
+--------------------------+
| |<>--{1..*}--[ ds:Signature ]
+--------------------------+
Figure 59: The SignatureData Class
The aggregate classes that constitutes SignatureData are:
Signature
One or more. An given signature. See Section 4.2 of [W3C.XMLSIG]
The SignatureData class has no attribute:
3.31. IndicatorData Class
The IndicatorData class describes the indicators identified from
analysis of an incident.
+--------------------------+
| IndicatorData |
+--------------------------+
| |<>--{1..*}--[ Indicator ]
+--------------------------+
Figure 60: The IndicatorData Class
The aggregate class that constitutes IndicatorData is:
Indicator
One or more. An indicator from the incident.
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The IndicatorData class has no attributes.
3.32. Indicator Class
The Indicator class describes a cyber indicator. An indicator
consists of observable features and phenomenon that aid in the
forensic or proactive detection of malicious activity, and associated
meta-data. This indicator can be described outright or reference
observable features and phenomenon described elsewhere in the
incident information. Portions of an incident description can be
composed to define an indicator, as can the indicators themselves.
+------------------------+
| Indicator |
+------------------------+
| ENUM restriction |<>----------[ IndicatorID ]
| STRING ext-restriction |<>--{0..1}--[ AlternativeIndicatorID ]
| |<>--{0..*}--[ Description ]
| |<>--{0..1}--[ StartTime ]
| |<>--{0..1}--[ EndTime ]
| |<>--{0..1}--[ Confidence ]
| |<>--{0..*}--[ Contact ]
| |<>--{0..1}--[ Observable ]
| |<>--{0..1}--[ ObservableReference ]
| |<>--{0..1}--[ IndicatorExpression ]
| |<>--{0..1}--[ IndicatorReference ]
| |<>--{0..*}--[ AdditionalData ]
+------------------------+
Figure 61: The Indicator Class
The aggregate classes that constitute Indicator are:
IndicatorID
One. An identifier for this indicator. See Section 3.32.1
AlternativeIndicatorID
Zero or one. An alternative identifier for this indicator. See
Section 3.32.2
Description
Zero or more. ML_STRING. A free-form textual description of the
indicator.
StartTime
Zero or one. DATETIME. A timestamp of the start of the time
period during which this indicator is valid.
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EndTime
Zero or one. DATETIME. A timestamp of the end of the time period
during which this indicator is valid.
Confidence
Zero or one. An estimate of the confidence in the quality of the
indicator. See Section 3.14.5.
Contact
Zero or more. Contact information for this indicator. See
Section 3.10.
Observable
Zero or one. An observable feature or phenomenon of this
indicator. See Section 3.32.3.
ObservableReference
Zero or one. A reference to a feature or phenomenon defined
elsewhere in the document. See Section 3.32.6.
IndicatorExpression
Zero or one. A composition of observables. See Section 3.32.4.
IndicatorReference
Zero or one. A reference to an indicator.
AdditionalData
Zero or more. Mechanism by which to extend the data model. See
Section 3.9
The Indicator class MUST have exactly one instance of an Observable,
IndicatorExpression, ObservableReference, or IndicatorReference
class.
The StartTime and EndTime classes can be used to define an interval
during which the indicator is valid. If both classes are present,
the indicator is consider valid only during the described interval.
If neither class is provided, the indicator is considered valid
during any time interval. If only a StartTime is provided, the
indicator is valid anytime after this timestamp. If only an EndTime
is provided, the indicator is valid anytime prior to this timestamp.
The Indicator class has two attributes:
restriction
Optional. ENUM. See Section 3.3.1.
ext-restriction
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Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
3.32.1. IndicatorID Class
The IndicatorID class identifies an indicator with a globally unique
identifier. The combination of the name and version attributes, and
the element content form this identifier. Indicators generated by
given CSIRT MUST NOT reuse the same value unless they are referencing
the same indicator.
+------------------+
| IndicatorID |
+------------------+
| ID |
| |
| STRING name |
| STRING version |
+------------------+
Figure 62: The IndicatorID Class
The IndicatorID class has two attributes:
name
Required. STRING. An identifier describing the CSIRT that
created the indicator. In order to have a globally unique CSIRT
name, the fully qualified domain name associated with the CSIRT
MUST be used. This format is identical to the IncidentID@name
attribute in Section 3.4.
version
Required. STRING. A version number of an indicator.
3.32.2. AlternativeIndicatorID Class
The AlternativeIndicatorID class lists alternative identifiers for an
indicator.
+-------------------------+
| AlternativeIndicatorID |
+-------------------------+
| ENUM restriction |<>--{1..*}--[ IndicatorReference ]
| STRING ext-restriction |
+-------------------------+
Figure 63: The AlternativeIndicatorID Class
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The aggregate class that constitutes AlternativeIndicatorID is:
IndicatorReference
One or more. A reference to an indicator.
The AlternativeIndicatorID class has two attributes:
restriction
Optional. ENUM. See Section 3.3.1.
ext-restriction
Optional. STRING. A means by which to extend the restriction
attribute. See Section 5.1.1.
3.32.3. Observable Class
The Observable class describes a feature and phenomenon that can be
observed or measured for the purposes of detecting malicious
behavior.
+-------------------+
| Observable |
+-------------------+
| |<>--{0..1}--[ Address ]
| |<>--{0..1}--[ DomainData ]
| |<>--{0..1}--[ Service ]
| |<>--{0..1}--[ EmailData ]
| |<>--{0..1}--[ ApplicationHeader ]
| |<>--{0..1}--[ WindowsRegistryKeysModified ]
| |<>--{0..1}--[ FileData ]
| |<>--{0..1}--[ CertificateData ]
| |<>--{0..1]--[ RegistryHandle ]
| |<>--{0..1}--[ RecordData ]
| |<>--{0..1}--[ EventData ]
| |<>--{0..1}--[ Incident ]
| |<>--{0..*}--[ Expectation ]
| |<>--{0..*}--[ Reference ]
| |<>--{0..1}--[ Assessment ]
| |<>--{0..1}--[ HistoryItem ]
| |<>--{0..1}--[ BulkObservable ]
| |<>--{0..*}--[ AdditionalData ]
+-------------------+
Figure 64: The Observable Class
The aggregate classes that constitute Observable are:
Address
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Zero or One. An Address observable. See Section 3.20.1.
DomainData
Zero or One. A DomainData observable. See Section 3.21.
Service
Zero or One. A Service observable. See Section 3.22.
EmailData
Zero or One. A EmailData observable. See Section 3.24.
ApplicationHeader
Zero or One. An ApplicationHeader observable. See
Section 3.22.2.
WindowsRegistryKeysModified
Zero or One. A WindowsRegistryKeysModified observable. See
Section 3.26.
FileData
Zero or One. A FileData observable. See Section 3.28.
CertificateData
Zero or One. A CertificateData observable. See Section 3.27.
RegistryHandle
Zero or One. A RegistryHandle observable. See Section 3.10.1.
RecordData
Zero or One. A RecordData observable. See Section 3.25.1.
EventData
Zero or One. An EventData observable. See Section 3.16.
Incident
Zero or One. An Incident observable. See Section 3.2.
EventData
Zero or One. An EventData observable. See Section 3.16.
Expectation
Zero or One. An Expectation observable. See Section 3.17.
Reference
Zero or One. A Reference observable. See Section 3.13.1.
Assessment
Zero or One. An Assessment observable. See Section 3.14.
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HistoryItem
Zero or One. A HistoryItem observable. See Section 3.15.1.
BulkObservable
Zero or One. A bulk list of observables. See Section 3.32.3.1.
AdditionalData
Zero or more. Mechanism by which to extend the data model. See
Section 3.9.
The Observable class MUST have exactly one of the possible child
classes.
The Observable class has no attributes.
3.32.3.1. BulkObservable Class
The BulkObservable class allows the bulk enumeration of single type
of observables without requiring each one to be encoded individually
in multiple instances of the same class. The type attribute
describes the type observable listed in the child BulkObservableList
class. The BulkObservableFormat class optionally provides additional
meta-data.
+---------------------------+
| BulkObservable |
+---------------------------+
| ENUM type |<>--{0..1}--[ BulkObservableFormat ]
| STRING ext-type |<>----------[ BulkObservableList ]
| |<>--{0..*}--[ AdditionalData ]
+---------------------------+
Figure 65: The BulkObservable Class
The aggregate classes that constitutes BulkObservable are:
BulkObservableFormat
Zero or one. Provides additional meta-data about the observables
enumerated in the BulkObservableList class.
BulkObservableList
One. STRING. A list of observables, one per line. Each line is
separated with either a LF character or CR-and-LF characters. The
type attribute will specify the which observables will be listed.
AdditionalData
Zero or more. Mechanism by which to extend the data model. See
Section 3.9.
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The BulkObservable class has two attributes:
type
Optional. ENUM. The type of the observable listed in the child
ObservableList class. These values are maintained in the
"BulkObservable-type" IANA registry per Table 1.
1. asn. Autonomous System Number (per the Address@category
attribute).
2. atm. Asynchronous Transfer Mode (ATM) address (per the
Address@category attribute).
3. e-mail. Electronic mail address (RFC 822) (per the
Address@category attribute).
4. ipv4-addr. IPv4 host address in dotted-decimal notation
(e.g., 192.0.2.1) (per the Address@category attribute).
5. ipv4-net. IPv4 network address in dotted-decimal notation,
slash, significant bits (e.g., 192.0.2.0/24) (per the
Address@category attribute).
6. ipv4-net-mask. IPv4 network address in dotted-decimal
notation, slash, network mask in dotted-decimal notation
(i.e., 192.0.2.0/255.255.255.0) (per the Address@category
attribute).
7. ipv6-addr. IPv6 host address (e.g., 2001:DB8::3) (per the
Address@category attribute).
8. ipv6-net. IPv6 network address, slash, significant bits
(e.g., 2001:DB8::/32) (per the Address@category attribute).
9. ipv6-net-mask. IPv6 network address, slash, network mask
(per the Address@category attribute).
10. mac. Media Access Control (MAC) address (i.e., a:b:c:d:e:f)
(per the Address@category attribute).
11. site-uri. A URL or URI for a resource (per the
Address@category attribute).
12. fqdn. Fully qualified domain name.
13. domain-name. A fully qualified domain name or part of a
name. (e.g., fqdn.example.com, example.com).
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14. domain-to-ipv4. A fqdn-to-IPv4 address mapping specified as
a comma separated list (e.g., "fqdn.example.com, 192.0.2.1").
15. domain-to-ipv6. A fqdn-to-IPv6 address mapping specified as
a comma separated list (e.g., "fqdn.example.com,
2001:DB8::3").
16. domain-to-ipv4-timestamp. Same as domain-to-ipv4 but with a
timestamp (in the DATETIME format) of the resolution (e.g.,
"fqdn.example.com, 192.0.2.1, 2015-06-11T00:38:31-06:00").
17. domain-to-ipv6-timestamp. Same as domain-to-ipv6 but with a
timestamp (in the DATETIME format) of the resolution (e.g.,
"fqdn.example.com, 2001:DB8::3, 2015-06-11T00:38:31-06:00").
18. ipv4-port. An IPv4 address, port and protocol tuple (e.g.,
192.0.2.1, 80, tcp). The protocol name corresponds to the
"Keyword" column in the [IANA.Protocols] registry.
19. ipv6-port. An IPv6 address, port and protocol tuple (e.g.,
2001:DB8::3, 80, tcp). The protocol name corresponds to the
"Keyword" column in the [IANA.Protocols] registry.
20. windows-reg-key. A Microsoft Windows Registry key.
21. file-hash. A file hash. The format of this hash is
described in the Hashclass that MUST be present in a sibling
BulkObservableFormat class.
22. email-x-mailer. An X-Mailer field from an email.
23. email-subject. An email subject line.
24. http-user-agent. A User Agent field from an HTTP request
header (e.g., "Mozilla/5.0 (Windows NT 6.3; WOW64; rv:38.0)
Gecko/20100101 Firefox/38.0").
25. http-request-uri. The Request URI from an HTTP request
header.
26. mutex. The name of a system mutex.
27. file-path. A file path (e.g., "/tmp/local/file",
"c:\windows\system32\file.sys")
28. user-name. A username.
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29. ext-value. An escape value used to extend this attribute.
See Section 5.1.1.
ext-type
Optional. STRING. A means by which to extend the type attribute.
See Section 5.1.1.
3.32.3.1.1. BulkObservableFormat Class
The ObservableFormat class specifies meta-data about the format of an
observable enumerated in a sibling BulkObservableList class.
+---------------------------+
| BulkObservableFormat |
+---------------------------+
| |<>--{0..1}--[ Hash ]
| |<>--{0..*}--[ AdditionalData ]
+---------------------------+
Figure 66: The BulkObservableFormat Class
The aggregate classes that constitutes BulkObservableFormat are:
Hash
Zero or one. Describes the format of a hash.
AdditionalData
Zero or more. Mechanism by which to extend the data model. See
Section 3.9.
The BulkObservableFormat class has no attributes.
Either Hash or AdditionalData MUST be present.
3.32.4. IndicatorExpression Class
The IndicatorExpression describes an expression composed of observed
phenomenon or features, or indicators. Elements of the expression
can be described directly, reference relevant data from other parts
of a given IODEF document, or reference previously defined
indicators.
All child classes of a given instance of IndicatorExpression form a
boolean algebraic expression where the operator between them is
determined by the operator attribute.
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+--------------------------+
| IndicatorExpression |
+--------------------------+
| ENUM operator |<>--{0..*}--[ IndicatorExpression ]
| |<>--{0..*}--[ Observable ]
| |<>--{0..*}--[ ObservableReference ]
| |<>--{0..*}--[ IndicatorReference ]
| |<>--{0..*}--[ AdditionalData ]
+--------------------------+
Figure 67: The IndicatorExpression Class
The aggregate classes that constitute IndicatorExpression are:
IndicatorExpression
Zero or more. An expression composed of other observables or
indicators.
Observable
Zero or more. A description of an observable.
ObservableReference
Zero or more. A reference to another observable.
IndicatorReference
Zero or more. A reference to another indicator.
AdditionalData
Zero or more. Mechanism by which to extend the data model. See
Section 3.9
The IndicatorExpression class has one attribute:
operator
Optional. ENUM. The operator to be applied between the child
elements. The default value is "and". These values are
maintained in the "IndicatorExpression-operator" IANA registry per
Table 1.
1. not. negation operator.
2. and. conjunction operator.
3. or. disjunction operator.
4. xor. exclusive disjunction operator.
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3.32.5. Expressions with IndicatorExpression
Boolean algebraic expressions can be used specify relationships
between observables and indicator. These expressions are constructed
through the use of the operator attribute and parent-child
relationships in IndicatorExpressions. These expressions should be
parsed as follows:
1. The operator specified by the operator attribute is applied
between each of the child elements of the immediate parent
IndicatorExpression element. If no operator attribute is
specified, it should be assumed to be an AND.
2. A nested IndicatorExpression element with a parent
IndicatorExpression is the equivalent of a parentheses in the
expression.
The following four examples illustrate these parsing rules:
1 :
2 [O1]: ..
3 [O2]: ..
4 :
Equivalent expression: (O1 AND O2)
Figure 68: Nested elements in an IndicatorExpression without an
operator attribute specified
1 :
2 [O1]: ..
3 [O2]: ..
4 :
Equivalent expression: (O1 OR O2)
Figure 69: Nested elements in an IndicatorExpression with an operator
attribute specified
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1 :
2 :
2 [O1]: ..
3 [O2]: ..
4 :
2 [O3]: ..
4 :
Equivalent expression: ((O1 OR O2) OR O3)
Figure 70: Nested elements with a recursive IndicatorExpression with
an operator attribute specified
1 :
2 :
2 [O1]: ..
3 [O2]: ..
4 :
4 :
Equivalent expression: (NOT (O1 AND O2))
Figure 71: A recursive IndicatorExpression with an operator attribute
specified
Invalid algebriac expressions while valid XML, MUST not be specified.
3.32.6. ObservableReference Class
The ObservableReference describes a reference to an observable
feature or phenomenon described elsewhere in the document.
This class has no content.
+-------------------------+
| ObservableReference |
+-------------------------+
| EMPTY |
| |
| IDREF uid-ref |
+-------------------------+
Figure 72: The ObservableReference Class
The ObservableReference class has one attribute:
uid-ref
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Required. IDREF. An identifier that serves as a reference to a
class in the IODEF document. The referenced class will have this
identifier set in the observable-id attribute.
3.32.7. IndicatorReference Class
The IndicatorReference describes a reference to an indicator. This
reference may be to an indicator described in the IODEF document or
in a previously exchanged IODEF document.
+--------------------------+
| IndicatorReference |
+--------------------------+
| EMPTY |
| |
| IDREF uid-ref |
| STRING euid-ref |
| STRING version |
+--------------------------+
Figure 73: The IndicatorReference Class
The IndicatorReference class has one attribute:
uid-ref
Optional. IDREF. An identifier that serves as a reference to an
Indicator class in the IODEF document. The referenced Indicator
class will have this identifier set in the IndicatorID class.
euid-ref
Optional. STRING. An identifier that references an IndicatorID
not in this IODEF document.
version
Optional. STRING. A version number of an indicator.
Either the uid-ref or the euid-ref attribute MUST be set.
4. Processing Considerations
This section defines additional requirements on creating and parsing
IODEF documents.
4.1. Encoding
Every IODEF document MUST begin with an XML declaration, and MUST
specify the XML version used. The character encoding MUST also be
explicitly specified. UTF-8 [RFC3629] SHOULD be used unless UTF-16
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[RFC2781] is necessary. Encodings other than UTF-8 and UTF-16 SHOULD
NOT be used. The IODEF conforms to all XML data encoding conventions
and constraints.
The XML declaration with no character encoding will read as follows:
When a character encoding is specified, the XML declaration will read
like the following:
Where "charset" is the name of the character encoding as registered
with the Internet Assigned Numbers Authority (IANA), see [RFC2978].
The following characters have special meaning in XML and MUST be
escaped with their entity reference equivalent: "&", "<", ">", "\""
(double quotation mark), and "'" (apostrophe). These entity
references are "&", "<", ">", """, and "'"
respectively.
4.2. IODEF Namespace
The IODEF schema declares a namespace of
"urn:ietf:params:xml:ns:iodef-2.0" and registers it per [W3C.XMLNS].
Each IODEF document MUST include a valid reference to the IODEF
schema using the "xsi:schemaLocation" attribute. An example of such
a declaration would look as follows:
A given extension attribute MUST NOT be set unless the corresponding
extensible attribute has been set to "ext-value".
5.1.2. Public Extension of Enumerated Values
Select enumerated value of the attributes defined in the data model
can be extended by adding entries to the corresponding IANA registry.
Table 1 enumerates these registries. Section 4.3 discusses the XML
Validation implications of these types of extensions.
5.2. Extending Classes
The classes of the data model can be extended only through the use of
the AdditionalData and RecordItem classes. These container classes,
collectively referred to as the extensible classes, are implemented
with the iodef:ExtensionType data type in the schema. They provide
the ability to have new atomic or XML-encoded data elements in all of
the top-level classes of the Incident class and a few of the more
complicated subordinate classes. As there are multiple instances of
the extensible classes in the data model, there is discretion on
where to add a new data element. It is RECOMMENDED that the
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extension be placed in the most closely related class to the new
information.
Extensions using the atomic data types (i.e., all values of the dtype
attributes other than "xml") MUST:
1. Set the element content of extensible class to the desired value,
and
2. Set the dtype attribute to correspond to the data type of the
element content.
The following guidelines exist for extensions using XML:
1. The element content of the extensible class MUST be set to the
desired value and the dtype attribute MUST be set to "xml".
2. The extension schema MUST declare a separate namespace. It is
RECOMMENDED that these extensions have the prefix "iodef-". This
recommendation makes readability of the document easier by
allowing the reader to infer which namespaces relate to IODEF by
inspection.
3. It is RECOMMENDED that extension schemas follow the naming
convention of the IODEF data model. This makes reading an
extended IODEF document look like any other IODEF document. The
names of all elements are capitalized. For elements with
composed names, a capital letter is used for each word.
Attribute names are lower case. Attributes with composed names
are separated by a hyphen.
4. Parsers that encounter an unrecognized element in a namespace
that they do support MUST reject the document as a syntax error.
5. There are security and performance implications in requiring
implementations to dynamically download schemas at run time.
Thus, implementations SHOULD NOT download schemas at runtime,
unless implementations take appropriate precautions and are
prepared for potentially significant network, processing, and
time-out demands.
6. Some users of the IODEF may have private schema definitions that
might not be available on the Internet. In this situation, if a
IODEF document leaks out of the private use space, references to
some of those document schemas may not be resolvable. This has
two implications. First, references to private schemas may never
resolve. As such, in addition to the suggestion that
implementations do not download schemas at runtime mentioned
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above, recipients MUST be prepared for a schema definition in an
IODEF document never to resolve.
The following schema and XML document excerpt provide a template for
an extension schema and its use in the IODEF document.
This example schema defines a namespace of "iodef-extension1" and a
single element named "newdata".
attributeFormDefault="unqualified"
elementFormDefault="qualified">
The following XML excerpt demonstrates the use of the above schema as
an extension to the IODEF.
...
Field that could not be represented elsewhere
If an unrecognized private extension is encountered in processing,
the recipient MAY reject the entire document as a syntax error.
6. Internationalization Issues
Internationalization and localization is of specific concern to the
IODEF, since it is only through collaboration, often across language
barriers, that certain incidents be resolved and threat information
shared. The IODEF supports this goal by depending on XML constructs,
and through explicit design choices in the data model.
Since IODEF is implemented as an XML Schema, it implicitly supports
all the different character encodings, such as UTF-8 and UTF-16,
possible with XML. Additionally, each IODEF document MUST specify
the language in which their contents are encoded. The language can
be specified with the attribute "xml:lang" (per Section 2.12 of
[W3C.XML]) in the top-level element (i.e., IODEF-Document) and
letting all other elements inherit that definition. All IODEF
classes with a free-form text definition (i.e., all those defined of
type iodef:MLStringType) can also specify a language different from
the rest of the document. The valid language codes for the
"xml:lang" attribute are described in [RFC5646].
The data model supports multiple translations of free-form text. For
classes where free-text is used for descriptive purposes (e.g.,
classes of the iodef:MLStringType type such as the Description
class), the given class always has a one-to-many cardinality to its
parent. The intent is to allow the identical text to be encoded in
different instances of the same class, but each being in a different
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language. This approach allows an IODEF document author to send
recipients speaking different languages an identical document. The
IODEF parser SHOULD extract the appropriate language relevant to the
recipient.
Related instances of a given iodef:MLStringType class that are
translations of each other are identified by a common identifier set
in the translation-id attribute. The example below shows three
instances of a Description class expressed in three difference
languages. The relationship between these three instances of the
Description class is conveyed by the common value of "1" in the
translation-id attribute.
...
English
Englisch
Anglais
While the intent of the data model is to provide internationalization
and localization, the intent is not to do so at the detriment of
interoperability. While the IODEF does support different languages,
the data model also relies heavily on standardized enumerated
attributes that can crudely approximate the contents of the document.
With this approach, a CSIRT should be able to make some sense of an
IODEF document it receives even if the text based data elements are
written in a language unfamiliar to the analyst.
7. Examples
This section provides examples of IODEF documents. These examples do
not necessarily represent the only way to encode particular
information.
7.1. Minimal Example
A document containing only the mandatory elements and attributes.
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492382
2015-07-18T09:00:00-05:00
contact@csirt.example.com
7.2. Indicators from a Campaign
An example of C2 domains from a given campaign.
897923
TA-12-AGGRESSIVE-BUTTERFLY
Aggressive Butterfly
C-2015-59405
Orange Giraffe
2015-10-02T11:18:00-05:00
Summarizes the Indicators of Compromise
for the Orange Giraffe campaign of the Aggressive
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Butterfly crime gang.
CSIRT for example.com
contact@csirt.example.com
G90823490
C2 domains
2014-12-02T11:18:00-05:00
kj290023j09r34.example.com
09ijk23jfj0k8.example.net
klknjwfjiowjefr923.example.org
oimireik79msd.example.org
7.3. Incident Report
An example of an incident report.
... TODO ...
8. The IODEF Schema
Incident Object Description Exchange Format v2.0, RFC5070bis
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9. Security Considerations
The IODEF data model itself does not directly introduce security
issues. Rather, it simply defines a representation for incident
information. As the data encoded by the IODEF might be considered
privacy sensitive by the parties exchanging the information or by
those described by it, care needs to be taken in ensuring the
appropriate disclosure during both document exchange and subsequent
processing. The former must be handled by a messaging format, but
the latter risk must be addressed by the systems that process, store,
and archive IODEF documents and information derived from them.
Executable content could be embedded into the IODEF document directly
or through an extension. The IODEF parser MUST handle this content
with care to prevent unintentional automated execution.
The contents of an IODEF document may include a request for action or
an IODEF parser may independently have logic to take certain actions
based on information that it finds. For this reason, care must be
taken by the parser to properly authenticate the recipient of the
document and ascribe an appropriate confidence to the data prior to
action.
The underlying messaging format and protocol used to exchange
instances of the IODEF MUST provide appropriate guarantees of
confidentiality, integrity, and authenticity. The use of a
standardized security protocol is encouraged. The Real-time Inter-
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network Defense (RID) protocol [RFC6545] and its associated transport
binding IODEF/RID over HTTP/TLS [RFC6546] provide such security.
In order to suggest data processing and handling guidelines of the
encoded information, the IODEF allows a document sender to convey a
privacy policy using the restriction attribute. The various
instances of this attribute allow different data elements of the
document to be covered by dissimilar policies. While flexible, it
must be stressed that this approach only serves as a guideline from
the sender, as the recipient is free to ignore it. The issue of
enforcement is not a technical problem.
10. IANA Considerations
This document registers a namespace, XML schema, and a number of
registries that map to enumerated values defined in the schema.
10.1. Namespace and Schema
This document uses URNs to describe an XML namespace and schema
conforming to a registry mechanism described in [RFC3688]
Registration for the IODEF namespace:
o URI: urn:ietf:params:xml:ns:iodef-2.0
o Registrant Contact: See the first author of the "Author's Address"
section of this document.
o XML: None. Namespace URIs do not represent an XML specification.
Registration for the IODEF XML schema:
o URI: urn:ietf:params:xml:schema:iodef-2.0
o Registrant Contact: See the first author of the "Author's Address"
section of this document.
o XML: See the "IODEF Schema" in Section 8 of this document.
10.2. Enumerated Value Registries
This document creates xx identically structured registries to be
managed by IANA:
o Name of the parent registry: "Incident Object Description Exchange
Format v2 (IODEF)"
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o URL of the registry: http://www.iana.org/assignments/iodef2
o Namespace format: A registry entry consists of:
* Value. An enumerated value for a given IODEF attribute.
* Description. A short description of the enumerated value.
* Reference. An optional list of URIs to further describe the
value.
o Allocation policy: Expert Review per [RFC5226]
The registries to be created are named in the table below in the
"Registry Name" column. The initial values for the Value and
Description fields of a given registry are listed in the "IV (Value)"
and "IV (Description)" columns respectively. The "IV (Value)" points
to a given schema attribute or type per Section 8. Each enumerated
value in the schema gets a corresponding entry in a given registry.
The "IV (Description)" points to a section in the text of this
document. The initial value of the Reference field of every registry
entry described below should be this document.
+-------------------------+-------------------------+---------------+
| Registry Name | IV (Value) | IV |
| | | (Description) |
+-------------------------+-------------------------+---------------+
| Restriction | iodef-restriction-type | Section 3.3.1 |
| | | |
| Incident-purpose | Incident@purpose | Section 3.2 |
| | | |
| Incident-status | Incident@status | Section 3.2 |
| | | |
| Contact-role | Contact@role | Section 3.10 |
| | | |
| Contact-type | Contact@type | Section 3.10 |
| | | |
| RegistryHandle-registry | RegistryHandle@registry | Section |
| | | 3.10.1 |
| | | |
| Expectation-action | iodef:action-type | Section 3.17 |
| | | |
| Discovery-source | Discovery@source | Section 3.12 |
| | | |
| SystemImpact-type | SystemImpact@type | Section |
| | | 3.14.1 |
| | | |
| BusinessImpact-severity | BusinessImpact@severity | Section |
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| | | 3.14.2 |
| | | |
| BusinessImpact-type | BusinessImpact@type | Section |
| | | 3.14.2 |
| | | |
| TimeImpact-metrics | TimeImpact@metric | Section |
| | | 3.14.3 |
| | | |
| TimeImpact-duration | iodef:duration-type | Section |
| | | 3.14.3 |
| | | |
| NodeRole-category | NodeRole@category | Section |
| | | 3.20.2 |
| | | |
| System-category | System@category | Section 3.19 |
| | | |
| System-ownership | System@ownership | Section 3.19 |
| | | |
| Address-category | Address@category | Section |
| | | 3.20.1 |
| | | |
| Counter-type | Counter@type | Section |
| | | 3.20.3 |
| | | |
| Counter-unit | Counter@unit | Section |
| | | 3.20.3 |
| | | |
| DomainData-system- | DomainData@system- | Section 3.21 |
| status | status | |
| | | |
| DomainData-domain- | DomainData@domain- | Section 3.21 |
| status | status | |
| | | |
| RelatedDNS-record-type | RelatedDNS@record-type | Section |
| | | 3.21.1 |
| | | |
| RecordPattern-type | RecordPattern@type | Section |
| | | 3.25.2 |
| | | |
| RecordPattern- | RecordPattern@offsetuni | Section |
| offsetunit | t | 3.25.2 |
| | | |
| Key-registryaction | Key@registryaction | Section |
| | | 3.26.1 |
| | | |
| HashData-scope | HashData@scope | Section 3.29 |
| | | |
| BulkObservable-type | BulkObservable@type | Section |
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| | | 3.32.3.1 |
| | | |
| IndicatorExpression- | IndicatorExpression@ope | Section |
| operator | rator | 3.32.4 |
| | | |
| AdditionalData-dtype | iodef:dtype-type | Section 3.9 |
| | | |
| ApplicationHeader- | iodef:proto-dtype-type | Section |
| proto-dtype | | 3.22.2 |
| | | |
| SoftwareReference-dtype | SoftwareReference | Section |
| | | 3.22.4 |
+-------------------------+-------------------------+---------------+
Table 1: IANA Enumerated Value Registries
11. Acknowledgments
The following groups and individuals, listed alphabetically,
contributed substantially to this document and should be recognized
for their efforts.
... TODO ...
12. References
12.1. Normative References
[W3C.XML] World Wide Web Consortium, "Extensible Markup Language
(XML) 1.0 (Second Edition)", W3C Recommendation , October
2000, .
[W3C.SCHEMA]
World Wide Web Consortium, "XML XML Schema Part 1:
Structures Second Edition", W3C Recommendation , October
2004, .
[W3C.SCHEMA.DTYPES]
World Wide Web Consortium, "XML Schema Part 2: Datatypes
Second Edition", W3C Recommendation , October 2004,
.
[W3C.XMLNS]
World Wide Web Consortium, "Namespaces in XML", W3C
Recommendation , January 1999,
.
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[W3C.XPATH]
World Wide Web Consortium, "XML Path Language (XPath)
2.0", W3C Candidate Recommendation , June 2006,
.
[W3C.XMLSIG]
World Wide Web Consortium, "XML Signature Syntax and
Processing 2.0", W3C Candidate Recommendation , June 2008,
.
[IEEE.POSIX]
Institute of Electrical and Electronics Engineers,
"Information Technology - Portable Operating System
Interface (POSIX) - Part 1: Base Definitions",
IEEE 1003.1, June 2001.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, March 1997.
[RFC5646] Philips, A. and M. Davis, "Tags for Identifying of
Languages", RFC 5646, September 2009.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifiers (URI): Generic Syntax", RFC 3986,
January 2005`.
[RFC2978] Freed, N. and J. Postel, "IANA Charset Registration
Procedures", BCP 2978, October 2000.
[RFC4519] Sciberras, A., "Schema for User Applications", RFC 4519,
June 2006.
[RFC5322] Resnick, P., "Internet Message Format", RFC 5322, October
2008.
[RFC3339] Klyne, G. and C. Newman, "Date and Time on the Internet:
Timestamps", RFC 3339, July 2002.
[RFC-ENUM]
Montville, A. and D. Black, "IODEF Enumeration Reference
Format", RFC ENUM, January 2015.
[RFC-SCI] Takahashi, T., Landfield, K., and Y. Kadobayashi, "An
Incident Object Description Exchange Format (IODEF)
Extension for Structured Cybersecurity Information",
RFC 5901, April 2014.
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[ISO8601] International Organization for Standardization,
"International Standard: Data elements and interchange
formats - Information interchange - Representation of
dates and times", ISO 8601, Second Edition, December 2000.
[ISO4217] International Organization for Standardization,
"International Standard: Codes for the representation of
currencies and funds, ISO 4217:2001", ISO 4217:2001,
August 2001.
[RFC3688] Mealling, M., "The IETF XML Registry", RFC 3688, January
2004.
[IANA.Ports]
Internet Assigned Numbers Authority, "Service Name and
Transport Protocol Port Number Registry", January 2014,
.
[IANA.Protocols]
Internet Assigned Numbers Authority, "Assigned Internet
Protocol Numbers", January 2014,
.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", RFC 3629, November 2003.
[RFC2781] Hoffman, P. and F. Yergeau, "UTF-16, an encoding of ISO
10646", RFC 2781, February 2000.
[IANA.Media]
Internet Assigned Numbers Authority, "Media Types", March
2015, .
12.2. Informative References
[RFC5070] Danyliw, R., Meijer, J., and Y. Demchenko, "Incident
Object Description Exchange Format", RFC 5070, December
2007.
[refs.requirements]
Keeni, G., Demchenko, Y., and R. Danyliw, "Requirements
for the Format for Incident Information Exchange (FINE)",
Work in Progress, June 2006.
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[RFC4765] Debar, H., Curry, D., Debar, H., and B. Feinstein,
"Intrusion Detection Message Exchange Format", RFC 4765,
March 2007.
[RFC6545] Moriarty, K., "Real-time Inter-network Defense (RID)",
RFC 6545, April 2012.
[RFC6546] Trammell, B., "Transport of Real-time Inter-network
Defense (RID) Messages over HTTP/TLS", RFC 6546, April
2012.
[RFC5901] Cain, P. and D. Jevans, "Extensions to the IODEF-Document
Class for Reporting Phishing", RFC 5901, July 2010.
[NIST800.61rev2]
Cichonski, P., Millar, T., Grance, T., and K. Scarfone,
"NIST Special Publication 800-61 Revision 2: Computer
Security Incident Handling Guide", January 2012,
.
[RFC3982] Newton, A. and M. Sanz, "IRIS: A Domain Registry (dreg)
Type for the Internet Registry Information Service
(IRIS)", RFC 3982, January 2005.
[KB310516]
Microsoft Corporation, "How to add, modify, or delete
registry subkeys and values by using a registration
entries (.reg) file", December 2007.
[RFC4180] Shafranovich, Y., "Common Format and MIME Type for Comma-
Separated Values (CSV) File", RFC 4180, October 2005.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", RFC 5226, May 2008.
Authors' Addresses
Roman Danyliw
CERT - Software Engineering Institute
Pittsburgh, PA
USA
EMail: rdd@cert.org
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Paul Stoecker
RSA
Reston, VA
USA
EMail: paul.stoecker@rsa.com
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