Suspicious CertUtil Commands

Identifies suspicious commands being used with certutil.exe. CertUtil is a native Windows component which is part of Certificate Services. CertUtil is often abused by attackers to live off the land for stealthier command and control or data exfiltration.

Rule type: eql

Rule indices:

winlogbeat-*
logs-endpoint.events.*
logs-windows.*
endgame-*

Severity: medium

Risk score: 47

Runs every: 5m

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

Elastic
Host
Windows
Threat Detection
Defense Evasion
Elastic Endgame

Version: 101

Rule authors:

Elastic
Austin Songer

Rule license: Elastic License v2

Investigation guide

edit

Rule query

edit

process where event.type == "start" and
  (process.name : "certutil.exe" or process.pe.original_file_name == "CertUtil.exe") and
  process.args : ("?decode", "?encode", "?urlcache", "?verifyctl", "?encodehex", "?decodehex", "?exportPFX")

Framework: MITRE ATT&CK^TM

Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
Technique:
- Name: Deobfuscate/Decode Files or Information
- ID: T1140
- Reference URL: https://attack.mitre.org/techniques/T1140/

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