Detection rules › Sigma

User Added To Group With CA Policy Modification Access

Status
test
Severity
medium
Log source
product azure, service auditlogs
Author
Mark Morowczynski '@markmorow', Thomas Detzner '@tdetzner'
Source
github.com/SigmaHQ/sigma

Monitor and alert on group membership additions of groups that have CA policy modification access

MITRE ATT&CK coverage

Rule body yaml

title: User Added To Group With CA Policy Modification Access
id: 91c95675-1f27-46d0-bead-d1ae96b97cd3
status: test
description: Monitor and alert on group membership additions 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: Add member from group
    condition: selection
falsepositives:
    - User removed from the group is approved
level: medium

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    properties.message: Add member from group

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
properties.messageeq
  • Add member from group