Active Directory Group Modification by SYSTEM

Identifies a user being added to an active directory group by the SYSTEM (S-1-5-18) user. This behavior can indicate that the attacker has achieved SYSTEM privileges in a domain controller, which attackers can obtain by exploiting vulnerabilities or abusing default group privileges (e.g., Server Operators), and is attempting to pivot to a domain account.

Rule type: eql

Rule indices:

winlogbeat-*
logs-system.security*
logs-windows.forwarded*

Severity: medium

Risk score: 47

Runs every: 5m

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References: None

Tags:

Domain: Endpoint
OS: Windows
Use Case: Threat Detection
Tactic: Persistence
Use Case: Active Directory Monitoring
Data Source: Active Directory
Data Source: System

Version: 2

Rule authors:

Elastic

Rule license: Elastic License v2

Rule query

edit

iam where winlog.api == "wineventlog" and event.code == "4728" and
winlog.event_data.SubjectUserSid : "S-1-5-18" and

/* DOMAIN_USERS and local groups */
not group.id : "S-1-5-21-*-513"

Framework: MITRE ATT&CK^TM

Tactic:
- Name: Persistence
- ID: TA0003
- Reference URL: https://attack.mitre.org/tactics/TA0003/
Technique:
- Name: Account Manipulation
- ID: T1098
- Reference URL: https://attack.mitre.org/techniques/T1098/
Tactic:
- Name: Privilege Escalation
- ID: TA0004
- Reference URL: https://attack.mitre.org/tactics/TA0004/
Technique:
- Name: Account Manipulation
- ID: T1098
- Reference URL: https://attack.mitre.org/techniques/T1098/

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