User Removed From Group With CA Policy Modification Access — Sigma Rule

Rule metadata and linked tags

Author: Mark Morowczynski '@markmorow', Thomas Detzner '@tdetzner'. Source status: test; severity: medium. Source dates: 2022-08-04 / not supplied.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: cabc8c5e153660f9fd9ecd2d4990eaaed83a611fd351cd5d61754fa858366a00

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: User Removed From Group With CA Policy Modification Access
id: 665e2d43-70dc-4ccc-9d27-026c9dd7ed9c
status: test
description: Monitor and alert on group membership removal of groups that have CA policy modification access
references:
    - https://learn.microsoft.com/en-us/entra/architecture/security-operations-infrastructure#conditional-access
author: Mark Morowczynski '@markmorow', Thomas Detzner '@tdetzner'
date: 2022-08-04
tags:
    - attack.privilege-escalation
    - attack.credential-access
    - attack.persistence
    - attack.defense-impairment
    - attack.t1548
    - attack.t1556
logsource:
    product: azure
    service: auditlogs
detection:
    selection:
        properties.message: Remove member from group
    condition: selection
falsepositives:
    - User removed from the group is approved
level: medium

Original YAML and metadata in JSON

False positives

• User removed from the group is approved

Source references

• https://learn.microsoft.com/en-us/entra/architecture/security-operations-infrastructure#conditional-access