Detection rules › Sigma

User Added to Local Administrator Group

Severity
medium
Author
Florian Roth (Nextron Systems)
Source
upstream

Detects the addition of a new member to the local administrator group, which could be legitimate activity or a sign of privilege escalation activity

MITRE ATT&CK coverage

TacticTechniques
Initial AccessT1078 Valid Accounts
PersistenceT1078 Valid Accounts, T1098 Account Manipulation
Privilege EscalationT1078 Valid Accounts, T1098 Account Manipulation
Defense EvasionT1078 Valid Accounts

Event coverage

ProviderEvent IDTitle
Security-Auditing4732A member was added to a security-enabled local group.

Stages and Predicates

Stage 1: all of selection_eid

Stage 2: all of selection_group

or:
TargetSid: S-1-5-32-544
TargetUserName|startswith: Administr

Stage 3: not 1 of filter_main_computer_accounts

SubjectUserName|endswith: '$'

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
SubjectUserNameends_with
  • $ corpus 18 (sigma 14, elastic 4)
TargetSideq
  • S-1-5-32-544
TargetUserNamestarts_with
  • Administr

Neighbors

Stricter alternatives (narrower than this rule)

The rules below may be useful if you find the current rule is too noisy / lacks specificity.