Detection rules › Sigma

Massive group membership changes detected

Status
experimental
Severity
medium
Time window
15m
Log source
product windows, service security
Author
mdecrevoisier
Source
github.com/mdecrevoisier/SIGMA-detection-rules

Detects scenarios where an attacker will add a compromised account into different domain groups in order to gain access to all the assets under the control of those concerned groups.

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1098 Account Manipulation

Event coverage

Rule body yaml

title: Massive group membership changes detected
name: massive_group_changes
description: Detects scenarios where an attacker will add a compromised account into different domain groups in order to gain access to all the assets under the control of those concerned groups.
references:
  - https://github.com/mdecrevoisier/EVTX-to-MITRE-Attack/tree/master/TA0003-Persistence/T1098.xxx-Account%20manipulation
tags:
  - attack.persistence
  - attack.t1098
author: mdecrevoisier
status: experimental
logsource:
  product: windows
  service: security
detection:
  selection:
    EventID:
      - 4728 # security global group member added
      - 4756 # universal group member added
      - 4732 # local and domain local group member added
  condition: selection
falsepositives:
  - Automatic scripts, provisionning accounts
level: medium

---
title: Massive group membership changes detected Count
status: experimental
correlation:
  type: value_count
  rules:
    - massive_group_changes # Referenced here
  group-by:
    - SubjectUserSid
  timespan: 15m
  condition:
    gte: 20
    field: TargetSid # Count how many different groups had a member added in a short period by the same user
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
  EventID:
    - 4728
    - 4756
    - 4732