[metadata]
creation_date = "2024/06/26"
integration = ["system", "windows"]
maturity = "production"
updated_date = "2024/06/26"

[rule]
author = ["Elastic"]
description = """
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.
"""
from = "now-9m"
index = ["winlogbeat-*", "logs-system.security*", "logs-windows.forwarded*"]
language = "eql"
license = "Elastic License v2"
name = "Active Directory Group Modification by SYSTEM"
risk_score = 47
rule_id = "6f024bde-7085-489b-8250-5957efdf1caf"
severity = "medium"
tags = [
    "Domain: Endpoint",
    "OS: Windows",
    "Use Case: Threat Detection",
    "Tactic: Persistence",
    "Use Case: Active Directory Monitoring",
    "Data Source: Active Directory",
]
timestamp_override = "event.ingested"
type = "eql"

query = '''
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"
'''


[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1098"
name = "Account Manipulation"
reference = "https://attack.mitre.org/techniques/T1098/"


[rule.threat.tactic]
id = "TA0003"
name = "Persistence"
reference = "https://attack.mitre.org/tactics/TA0003/"

[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1098"
name = "Account Manipulation"
reference = "https://attack.mitre.org/techniques/T1098/"


[rule.threat.tactic]
id = "TA0004"
name = "Privilege Escalation"
reference = "https://attack.mitre.org/tactics/TA0004/"