Detection rules › Kusto Query Language

Clearing of forensic evidence from event logs using wevtutil

Source
upstream

This query checks for attempts to clear at least 10 log entries from event logs using wevtutil. Clearing event logs can be a sign of ransomware activity, as ransomware often attempts to cover its tracks by deleting logs.

MITRE ATT&CK coverage

TacticTechniques
Defense EvasionT1070 Indicator Removal

Event coverage

ProviderEvent IDTitle
Sysmon1Process creation
Security-Auditing4688A new process has been created.
Defender-DeviceProcessEvents9001000Process activity (any)

Stages and Predicates

Stage 1: source

DeviceProcessEvents

Stage 2: where

and
  ProcessCommandLine match "CL"
  ProcessCommandLine match "WEVTUTIL"

Stage 3: summarize

Stage 4: where

LogClearCount gt "10"

Stage 5: extend

Stage 6: extend

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
LogClearCountgt
  • 10
ProcessCommandLinematch
  • CL
  • WEVTUTIL