Detection rules › Sigma

Event log clear attempt (command)

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 clear the event logs.

MITRE ATT&CK coverage

Event coverage

Rule body yaml

title: Event log clear attempt (command)
description: Detects scenarios where an attacker attempts to clear the event logs.
references:
- https://github.com/mdecrevoisier/EVTX-to-MITRE-Attack/tree/master/TA0005-Defense%20Evasion/T1070.001-Clear%20Windows%20event%20logs
- https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/wevtutil
- https://www.zscaler.com/blogs/security-research/technical-analysis-crytox-ransomware
- https://www.microsoft.com/en-us/security/blog/2022/06/13/the-many-lives-of-blackcat-ransomware/
- https://www.elastic.co/security-labs/invisible-miners-unveiling-ghostengine
tags:
- attack.defense_evasion
- attack.t1070.001
author: mdecrevoisier
status: experimental
logsource:
  product: windows
  category: process_creation
detection: # Full command: wevtutil el | Foreach-Object {Write-Host "Clearing $_"; wevtutil cl "$_"}
  selection:
    NewProcessName|endswith: '\wevtutil.exe'
    CommandLine|contains:
      - 'clear-log'
      - cl # reduced command
  condition: selection
falsepositives:
- None
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
  NewProcessName|endswith: '\wevtutil.exe'
  CommandLine|contains:
    - 'clear-log'
    - cl

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
  • cl corpus 3 (sigma 2, kusto 1)
  • clear-log corpus 2 (sigma 2)
NewProcessNameends_with
  • \wevtutil.exe corpus 9 (sigma 9)