Anomalous Token — Sigma Rule

Rule metadata and linked tags

Author: Mark Morowczynski '@markmorow'. Source status: test; severity: high. Source dates: 2023-08-07 / not supplied.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 177c760939b2ebbe2a787c95658019cdf4d2524a12c2ef79d95bf4bda4716bb9

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: Anomalous Token
id: 6555754e-5e7f-4a67-ad1c-4041c413a007
status: test
description: Indicates that there are abnormal characteristics in the token such as an unusual token lifetime or a token that is played from an unfamiliar location.
references:
    - https://learn.microsoft.com/en-us/entra/id-protection/concept-identity-protection-risks#anomalous-token
    - https://learn.microsoft.com/en-us/entra/architecture/security-operations-user-accounts#unusual-sign-ins
author: Mark Morowczynski '@markmorow'
date: 2023-08-07
tags:
    - attack.t1528
    - attack.credential-access
logsource:
    product: azure
    service: riskdetection
detection:
    selection:
        riskEventType: 'anomalousToken'
    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#anomalous-token
• https://learn.microsoft.com/en-us/entra/architecture/security-operations-user-accounts#unusual-sign-ins