Detection rules › Sigma
High risk local/domain local group membership change
Detects scenarios where a suspicious group membership is changed. Having Microsoft LAPS installed may trigger false positive events for the builtin administrators group triggered by the system account (S-1-5-18).
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Persistence | T1098 Account Manipulation |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Security-Auditing | Event ID 4732 | A member was added to a security-enabled local group. |
Rule body yaml
title: High risk local/domain local group membership change
description: Detects scenarios where a suspicious group membership is changed. Having Microsoft LAPS installed may trigger false positive events for the builtin administrators group triggered by the system account (S-1-5-18).
references:
- https://github.com/mdecrevoisier/EVTX-to-MITRE-Attack/tree/master/TA0003-Persistence/T1098.xxx-Account%20manipulation
- https://ss64.com/nt/syntax-groups.html
- https://docs.microsoft.com/en-us/windows/security/identity-protection/access-control/security-identifiers
tags:
- attack.persistence
- attack.t1098
author: mdecrevoisier
status: experimental
logsource:
product: windows
service: security
detection:
selection:
EventID: 4732 # local and domain local group
TargetSid|startswith: 'S-1-5-32'
TargetSid|endswith:
- '-544' # Administrators
- '-547' # Power Users
- '-548' # Account Operators
- '-549' # Server Operators
- '-551' # Backup Operators
- '-578' # Hyper-V Administrators
filter:
SubjectUserSid: 'S-1-5-18' # LAPS or others IAM solutions may trigger this as a false positive
condition: selection and not filter
falsepositives:
- Administrator activity
level: high
Stages and Predicates
Stage 0: condition
selection and not filterStage 1: selection
selection:
EventID: 4732
TargetSid|startswith: 'S-1-5-32'
TargetSid|endswith:
- '-544'
- '-547'
- '-548'
- '-549'
- '-551'
- '-578'
Stage 2: not filter
filter:
SubjectUserSid: 'S-1-5-18'
Exclusions
Top-level NOT(...) conjuncts: predicates this rule actively suppresses.
| Field | Kind | Excluded values |
|---|---|---|
SubjectUserSid | eq | S-1-5-18 |
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.