SAML Token Issuer Anomaly — Sigma Rule

Rule metadata and linked tags

Author: Mark Morowczynski '@markmorow', Gloria Lee, '@gleeiamglo'. Source status: test; severity: high. Source dates: 2023-09-03 / not supplied.

{
  "product": "azure",
  "service": "riskdetection"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 59c9732386a32ee17c66b5511b60516d062c38c17649d99b83ef4d15c4ac5759

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: SAML Token Issuer Anomaly
id: e3393cba-31f0-4207-831e-aef90ab17a8c
status: test
description: Indicates the SAML token issuer for the associated SAML token is potentially compromised. The claims included in the token are unusual or match known attacker patterns
references:
    - https://learn.microsoft.com/en-us/entra/id-protection/concept-identity-protection-risks#token-issuer-anomaly
    - https://learn.microsoft.com/en-us/entra/architecture/security-operations-user-accounts#unusual-sign-ins
author: Mark Morowczynski '@markmorow', Gloria Lee, '@gleeiamglo'
date: 2023-09-03
tags:
    - attack.t1606
    - attack.credential-access
logsource:
    product: azure
    service: riskdetection
detection:
    selection:
        riskEventType: 'tokenIssuerAnomaly'
    condition: selection
falsepositives:
    - We recommend investigating the sessions flagged by this detection in the context of other sign-ins from the user.
level: high

Original YAML and metadata in JSON

False positives

• We recommend investigating the sessions flagged by this detection in the context of other sign-ins from the user.

Source references

• https://learn.microsoft.com/en-us/entra/id-protection/concept-identity-protection-risks#token-issuer-anomaly
• https://learn.microsoft.com/en-us/entra/architecture/security-operations-user-accounts#unusual-sign-ins