Encoding or Decoding Files via CertUtiledit

Identifies the use of certutil.exe to encode or decode data. CertUtil is a native Windows component which is part of Certificate Services. CertUtil is often abused by attackers to encode or decode base64 data for stealthier command and control or exfiltration.

Rule type: query

Rule indices:

  • winlogbeat-*

Severity: medium

Risk score: 47

Runs every: 5 minutes

Searches indices from: now-6m (Date Math format, see also Additional look-back time)

Maximum signals per execution: 100


  • Elastic
  • Windows

Version: 2 (version history)

Added (Elastic Stack release): 7.6.0

Last modified (Elastic Stack release): 7.7.0

Rule queryedit

event.action:"Process Create (rule: ProcessCreate)" and
process.name:certutil.exe and process.args:(-decode or -encode or
/decode or /encode)

Threat mappingedit


Rule version historyedit

Version 2 (7.7.0 release)

Updated query, changed from:

event.action:"Process Create (rule: ProcessCreate)" and
process.name:"certutil.exe" and process.args:("-encode" or "/encode"
or "-decode" or "/decode")