Detection rules › Sigma

Audit policy disabled by command line

Status
experimental
Severity
high
Log source
product windows, category process_creation
Author
mdecrevoisier
Source
github.com/mdecrevoisier/SIGMA-detection-rules

Detects scenarios where an attacker attempts to disbale or clear the audit policy for defense evasion purposes.

MITRE ATT&CK coverage

Event coverage

Rule body yaml

title: Audit policy disabled by command line
description: Detects scenarios where an attacker attempts to disbale or clear the audit policy for defense evasion purposes.
references:
- https://github.com/mdecrevoisier/EVTX-to-MITRE-Attack/tree/master/TA0005-Defense%20Evasion/T1562.002-Disable%20Windows%20Event%20Logging
- https://searchitchannel.techtarget.com/feature/Using-AuditPol-to-audit-Windows-users-and-set-policies
tags:
- attack.defense_evasion
- attack.t1562.002 # Impair Defenses: Disable Windows Event Logging 
author: mdecrevoisier
status: experimental
logsource:
  product: windows
  category: process_creation
detection:
  selection:
    NewProcessName|endswith: '\auditpol.exe'
    CommandLine|contains:
      - clear   # "auditpol /clear /y"
      - disable # "auditpol /set /category:* /success:disable /failure:disable"
  condition: selection
falsepositives:
- Administrator debugging audit policy
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
  NewProcessName|endswith: '\auditpol.exe'
  CommandLine|contains:
    - clear
    - disable

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
CommandLinematch
  • clear corpus 4 (sigma 3, kusto 1)
  • disable corpus 13 (sigma 10, splunk 3)
NewProcessNameends_with
  • \auditpol.exe corpus 3 (sigma 3)