Indicator Object

Indicator An indicator is a test, or a collection of judgements that define criteria for identifying the activity, or presence of malware, or other unwanted software.

We follow the STiX IndicatorType closely, with the exception of not including observables within the indicator, and preferring a specification object encoded in JSON as opposed to an opaque implementation block.

Additional, you will want to either define judgements against Observables that are linked to this indicator, with the ID in the indicators field of those Judgements, or you can provide a specification value.

Property	Type	Description	Required?
id	String	Globally unique URI identifying this object.	✓
producer	ShortStringString		✓
schema_version	String	CTIM schema version for this entity.	✓
type	IndicatorTypeIdentifierString	The fixed value indicator	✓
valid_time	ValidTime Object	The time range during which this Indicator is considered valid.	✓
composite_indicator_expression	CompositeIndicatorExpression Object
confidence	HighMedLowString	level of confidence held in the accuracy of this Indicator.
description	MarkdownString	A description of object, which may be detailed.
external_ids	String List	It is used to store a list of external identifiers that can be linked to the incident, providing a reliable and manageable way to correlate and group related events across multiple data sources. It is especially useful in larger organizations that rely on multiple security information and event management (SIEM) systems to detect security incidents. For instance, it can be used to track events across different network sensors, intrusion detection and prevention systems (IDPS), or log management platforms. The field can also be used to facilitate automation and orchestration workflows, where additional information can be shared among incident management systems. It can be used to cross-reference with other external tools such as threat intelligence feeds and vulnerability scanners.
external_references	ExternalReference Object List	Specifies a list of external references which refers to non-CTIM information. Similar to external_ids field with major differences: - external_ids field is used to store a list of external identifiers that can be used to link entities across different data sources. These identifiers are typically standardized and well-known, such as CVE IDs, US-CERT advisories, or other industry-standard threat intelligence feeds. The external_ids field can be used to facilitate automation and orchestration workflows, where additional information can be shared among incident management systems. - external_references field, on the other hand, is used to provide a more general mechanism for linking entities to external sources of information. The external_references field can include references to blog posts, articles, external documents, threat intelligence reports, and other sources of information that may not have a standardized format or identifier.
indicator_type	IndicatorTypeString List	Specifies the type or types for this Indicator.
kill_chain_phases	KillChainPhase Object List	Relevant kill chain phases indicated by this Indicator.
language	ShortStringString	The language field is used to specify the primary language of the affected system or the target of an attack. It can be used to provide additional context and information about the entity. The primary purpose of this field is to help analysts filter and prioritize entities based on their knowledge and expertise of different languages. For example, if an incident involves an attack on a system in a country where a specific language is predominant, the language field can be used to indicate that language, which can help analysts to quickly identify and respond to incidents that may be geographically or culturally relevant. This information can be used to prioritize incidents based on their potential impact. The language field can also be used to help with correlation of incidents across different systems and regions, as well as to help with data analysis and reporting.
likely_impact	LongStringString	Likely potential impact within the relevant context if this Indicator were to occur.
negate	Boolean	Specifies the absence of the pattern.
revision	Integer	A monotonically increasing revision, incremented each time the object is changed.
severity	SeverityString
short_description	MedStringString	A single line, short summary of the object.
source	MedStringString	Represents the source of the intelligence that led to the creation of the entity.
source_uri	String	URI of the source of the intelligence that led to the creation of the entity.
specification	JudgementSpecification Object
tags	ShortStringString List	Descriptors for this indicator.
test_mechanisms	MedStringString List	Test Mechanisms effective at identifying the cyber Observables specified in this cyber threat Indicator.
timestamp	Inst (Date)	The time this object was created at, or last modified.
title	ShortStringString	A short title for this object, used as primary display and reference value.
tlp	TLPString	TLP stands for Traffic Light Protocol, which indicates precisely how a resource is intended to be shared, replicated, copied, etc. It is used to indicate the sensitivity of the information contained within the message. This allows recipients to determine the appropriate handling and dissemination of the information based on their clearance level and need-to-know. For example, an entity containing information about a critical vulnerability in a widely-used software might be marked as red, indicating that it should only be shared with a small group of highly trusted individuals who need to know in order to take appropriate action. On the other hand, a message containing more general information about security threats might be marked as amber or green, indicating that it can be shared more broadly within an organization.

• Reference: IndicatorType

Property composite_indicator_expression ∷ CompositeIndicatorExpression Object

• This entry is optional

• CompositeIndicatorExpression Object Value
  • Details: CompositeIndicatorExpression Object

Property confidence ∷ HighMedLowString

level of confidence held in the accuracy of this Indicator.

• This entry is optional

  • Allowed Values:
    • High
    • Info
    • Low
    • Medium
    • None
    • Unknown
  • Reference: HighMedLowVocab

Property description ∷ MarkdownString

A description of object, which may be detailed.

• This entry is optional

  • Markdown Markdown string with at most 5000 characters.

Property external_ids ∷ String List

It is used to store a list of external identifiers that can be linked to the incident, providing a reliable and manageable way to correlate and group related events across multiple data sources. It is especially useful in larger organizations that rely on multiple security information and event management (SIEM) systems to detect security incidents. For instance, it can be used to track events across different network sensors, intrusion detection and prevention systems (IDPS), or log management platforms. The field can also be used to facilitate automation and orchestration workflows, where additional information can be shared among incident management systems. It can be used to cross-reference with other external tools such as threat intelligence feeds and vulnerability scanners.

• This entry is optional
• This entry's type is sequential (allows zero or more values)

Property external_references ∷ ExternalReference Object List

Specifies a list of external references which refers to non-CTIM information.

Similar to external_ids field with major differences:

• external_ids field is used to store a list of external identifiers that can be used to link entities across different data sources. These identifiers are typically standardized and well-known, such as CVE IDs, US-CERT advisories, or other industry-standard threat intelligence feeds. The external_ids field can be used to facilitate automation and orchestration workflows, where additional information can be shared among incident management systems.

• external_references field, on the other hand, is used to provide a more general mechanism for linking entities to external sources of information. The external_references field can include references to blog posts, articles, external documents, threat intelligence reports, and other sources of information that may not have a standardized format or identifier.

• This entry is optional
• This entry's type is sequential (allows zero or more values)

• ExternalReference Object Value
  • Details: ExternalReference Object

Property id ∷ String

Globally unique URI identifying this object.

• This entry is required

  • IDs are URIs, for example https://www.domain.com/ctia/judgement/judgement-de305d54-75b4-431b-adb2-eb6b9e546014 for a Judgement. This ID type compares to the STIX id field. The optional STIX idref field is not used.

Property indicator_type ∷ IndicatorTypeString List

Specifies the type or types for this Indicator.

• This entry is optional

• This entry's type is sequential (allows zero or more values)

  • Allowed Values:
    • Anonymization
    • C2
    • Compromised PKI Certificate
    • Domain Watchlist
    • Exfiltration
    • File Hash Watchlist
    • Host Characteristics
    • IMEI Watchlist
    • IMSI Watchlist
    • IP Watchlist
    • Login Name
    • Malicious E-mail
    • Malware Artifacts
    • Private Threat Feed
    • URL Watchlist
  • Reference: IndicatorTypeVocab

Property kill_chain_phases ∷ KillChainPhase Object List

Relevant kill chain phases indicated by this Indicator.

• This entry is optional
• This entry's type is sequential (allows zero or more values)
• Dev Notes: simplified

• KillChainPhase Object Value
  • Details: KillChainPhase Object

Property language ∷ ShortStringString

The language field is used to specify the primary language of the affected system or the target of an attack. It can be used to provide additional context and information about the entity. The primary purpose of this field is to help analysts filter and prioritize entities based on their knowledge and expertise of different languages.

For example, if an incident involves an attack on a system in a country where a specific language is predominant, the language field can be used to indicate that language, which can help analysts to quickly identify and respond to incidents that may be geographically or culturally relevant. This information can be used to prioritize incidents based on their potential impact. The language field can also be used to help with correlation of incidents across different systems and regions, as well as to help with data analysis and reporting.

• This entry is optional

  • ShortString String with at most 1024 characters.

Property likely_impact ∷ LongStringString

Likely potential impact within the relevant context if this Indicator were to occur.

• This entry is optional

  • LongString String with at most 5000 characters.

Property negate ∷ Boolean

Specifies the absence of the pattern.

• This entry is optional

Property producer ∷ ShortStringString

• This entry is required

• Dev Notes: TODO - Document what is supposed to be in this field!

  • ShortString String with at most 1024 characters.

Property revision ∷ Integer

A monotonically increasing revision, incremented each time the object is changed.

• This entry is optional

  • Zero, or a positive integer.

Property schema_version ∷ String

CTIM schema version for this entity.

• This entry is required

  • A semantic version matching the CTIM version against which this object should be valid.

Property severity ∷ SeverityString

• This entry is optional

  • Allowed Values:
    • Critical
    • High
    • Info
    • Low
    • Medium
    • None
    • Unknown

Property short_description ∷ MedStringString

A single line, short summary of the object.

• This entry is optional

  • MedString String with at most 2048 characters.

Property source ∷ MedStringString

Represents the source of the intelligence that led to the creation of the entity.

• This entry is optional

  • MedString String with at most 2048 characters.

Property source_uri ∷ String

URI of the source of the intelligence that led to the creation of the entity.

• This entry is optional

  • A URI

Property specification ∷ Either

• This entry is optional

  • Only one of the following schemas will match

• JudgementSpecification Object Value
  • Details: JudgementSpecification Object

• ThreatBrainSpecification Object Value
  • Details: ThreatBrainSpecification Object

• SnortSpecification Object Value
  • Details: SnortSpecification Object

• SIOCSpecification Object Value
  • Details: SIOCSpecification Object

• OpenIOCSpecification Object Value
  • Details: OpenIOCSpecification Object

Property tags ∷ ShortStringString List

Descriptors for this indicator.

• This entry is optional

• This entry's type is sequential (allows zero or more values)

  • ShortString String with at most 1024 characters.

Property test_mechanisms ∷ MedStringString List

Test Mechanisms effective at identifying the cyber Observables specified in this cyber threat Indicator.

• This entry is optional

• This entry's type is sequential (allows zero or more values)

• Dev Notes: simplified

  • MedString String with at most 2048 characters.

Property timestamp ∷ Inst (Date)

The time this object was created at, or last modified.

• This entry is optional

  • ISO8601 Timestamp Schema definition for all date or timestamp values. Serialized as a string, the field should follow the rules of the ISO8601 standard.

Property title ∷ ShortStringString

A short title for this object, used as primary display and reference value.

• This entry is optional

  • ShortString String with at most 1024 characters.

Property tlp ∷ TLPString

TLP stands for Traffic Light Protocol, which indicates precisely how a resource is intended to be shared, replicated, copied, etc.

It is used to indicate the sensitivity of the information contained within the message. This allows recipients to determine the appropriate handling and dissemination of the information based on their clearance level and need-to-know.

For example, an entity containing information about a critical vulnerability in a widely-used software might be marked as red, indicating that it should only be shared with a small group of highly trusted individuals who need to know in order to take appropriate action. On the other hand, a message containing more general information about security threats might be marked as amber or green, indicating that it can be shared more broadly within an organization.

• This entry is optional

  • Allowed Values:
    • amber
    • green
    • red
    • white

Property type ∷ IndicatorTypeIdentifierString

The fixed value indicator

• This entry is required

  • IndicatorTypeIdentifier The fixed value "indicator"
  • Must equal: "indicator"

Property valid_time ∷ ValidTime Object

The time range during which this Indicator is considered valid.

• This entry is required

• ValidTime Object Value
  • Details: ValidTime Object

ExternalReference Object

ExternalReference External references are used to describe pointers to information represented outside of CTIM. For example, a Malware object could use an external reference to indicate an ID for that malware in an external database or a report could use references to represent source material.

Property	Type	Description	Required?
source_name	MedStringString	The source within which the external-reference is defined (system, registry, organization, etc.)	✓
description	MarkdownString
external_id	String	An identifier for the external reference content.
hashes	String List	Specifies a dictionary of hashes for the contents of the url.
url	String	A URL reference to an external resource.

• Reference: External Reference

Property description ∷ MarkdownString

• This entry is optional

  • Markdown Markdown string with at most 5000 characters.

Property external_id ∷ String

An identifier for the external reference content.

• This entry is optional

Property hashes ∷ String List

Specifies a dictionary of hashes for the contents of the url.

• This entry is optional
• This entry's type is sequential (allows zero or more values)

Property source_name ∷ MedStringString

The source within which the external-reference is defined (system, registry, organization, etc.)

• This entry is required

  • MedString String with at most 2048 characters.

Property url ∷ String

A URL reference to an external resource.

• This entry is optional

  • A URI

ValidTime Object

ValidTime Period of time when a cyber observation is valid.

Property	Type	Description	Required?
end_time	Inst (Date)	If end_time is not present, then the valid time position of the object does not have an upper bound.
start_time	Inst (Date)	If not present, the valid time position of the indicator does not have an upper bound.

• Reference: ValidTimeType

Property end_time ∷ Inst (Date)

If end_time is not present, then the valid time position of the object does not have an upper bound.

• This entry is optional

  • ISO8601 Timestamp Schema definition for all date or timestamp values. Serialized as a string, the field should follow the rules of the ISO8601 standard.

Property start_time ∷ Inst (Date)

If not present, the valid time position of the indicator does not have an upper bound.

• This entry is optional

  • ISO8601 Timestamp Schema definition for all date or timestamp values. Serialized as a string, the field should follow the rules of the ISO8601 standard.

CompositeIndicatorExpression Object

Property	Type	Description	Required?
indicator_ids	String List		✓
operator	BooleanOperatorString		✓

• Reference: CompositeIndicatorExpressionType

Property indicator_ids ∷ String List

• This entry is required

• This entry's type is sequential (allows zero or more values)

  • A URI leading to an indicator.

Property operator ∷ BooleanOperatorString

• This entry is required

  • Allowed Values:
    • and
    • not
    • or

KillChainPhase Object

KillChainPhase The kill-chain-phase represents a phase in a kill chain, which describes the various phases an attacker may undertake in order to achieve their objectives.

Property	Type	Description	Required?
kill_chain_name	String	The name of the kill chain.	✓
phase_name	String	The name of the phase in the kill chain.	✓

• Reference: Kill Chain Phase

Property kill_chain_name ∷ String

The name of the kill chain.

• This entry is required

  • SHOULD be all lowercase (where lowercase is defined by the locality conventions) and SHOULD use hyphens instead of spaces or underscores as word separators.
  • Must equal: "lockheed-martin-cyber-kill-chain"
  • Reference: Open Vocabulary

Property phase_name ∷ String

The name of the phase in the kill chain.

• This entry is required

  • SHOULD be all lowercase (where lowercase is defined by the locality conventions) and SHOULD use hyphens instead of spaces or underscores as word separators.
  • Allowed Values:
    • actions-on-objective
    • command-and-control
    • delivery
    • exploitation
    • installation
    • reconnaissance
    • weaponization
  • Reference: Open Vocabulary

JudgementSpecification Object

JudgementSpecification An indicator based on a list of judgements. If any of the Observables in it's judgements are encountered, than it may be matches against. If there are any required judgements, they all must be matched in order for the indicator to be considered a match.

Property	Type	Description	Required?
judgements	String List		✓
required_judgements	RelatedJudgement Object List		✓
type	JudgementSpecificationTypeString		✓

Property judgements ∷ String List

• This entry is required

• This entry's type is sequential (allows zero or more values)

  • A URI leading to a judgement.

Property required_judgements ∷ RelatedJudgement Object List

• This entry is required
• This entry's type is sequential (allows zero or more values)

• RelatedJudgement Object Value
  • Details: RelatedJudgement Object

Property type ∷ JudgementSpecificationTypeString

• This entry is required

  • Must equal: "Judgement"

RelatedJudgement Object

Property	Type	Description	Required?
judgement_id	String		✓
confidence	HighMedLowString
relationship	String
source	String

Property confidence ∷ HighMedLowString

• This entry is optional

  • Allowed Values:
    • High
    • Info
    • Low
    • Medium
    • None
    • Unknown
  • Reference: HighMedLowVocab

Property judgement_id ∷ String

• This entry is required

  • A URI leading to a judgement.

Property relationship ∷ String

• This entry is optional

Property source ∷ String

• This entry is optional

ThreatBrainSpecification Object

ThreatBrainSpecification An indicator which runs in threatbrain...

Property	Type	Description	Required?
type	ThreatBrainSpecificationTypeString		✓
variables	String List		✓
query	String

Property query ∷ String

• This entry is optional

Property type ∷ ThreatBrainSpecificationTypeString

• This entry is required

  • Must equal: "ThreatBrain"

Property variables ∷ String List

• This entry is required
• This entry's type is sequential (allows zero or more values)

SnortSpecification Object

SnortSpecification An indicator which runs in snort...

Property	Type	Description	Required?
snort_sig	String		✓
type	SnortSpecificationTypeString		✓

Property snort_sig ∷ String

• This entry is required

Property type ∷ SnortSpecificationTypeString

• This entry is required

  • Must equal: "Snort"

SIOCSpecification Object

SIOCSpecification An indicator which runs in snort...

Property	Type	Description	Required?
SIOC	String		✓
type	SIOCSpecificationTypeString		✓

Property SIOC ∷ String

• This entry is required

Property type ∷ SIOCSpecificationTypeString

• This entry is required

  • Must equal: "SIOC"

OpenIOCSpecification Object

OpenIOCSpecification An indicator which contains an XML blob of an openIOC indicator.

Property	Type	Description	Required?
open_IOC	String		✓
type	OpenIOCSpecificationTypeString		✓

Property open_IOC ∷ String

• This entry is required

Property type ∷ OpenIOCSpecificationTypeString

• This entry is required

  • Must equal: "OpenIOC"