Network Connection via Certutiledit

Identifies certutil.exe making a network connection. Adversaries could abuse certutil.exe to download a certificate or malware from a remote URL.

Rule type: eql

Rule indices:

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

Severity: low

Risk score: 21

Runs every: 5 minutes

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

Maximum alerts per execution: 100

Tags:

  • Elastic
  • Host
  • Windows
  • Threat Detection
  • Command and Control

Version: 5 (version history)

Added (Elastic Stack release): 7.7.0

Last modified (Elastic Stack release): 7.12.0

Rule authors: Elastic

Rule license: Elastic License v2

Rule queryedit

sequence by process.entity_id [process where process.name :
"certutil.exe" and event.type == "start"] [network where
process.name : "certutil.exe" and not cidrmatch(destination.ip,
"10.0.0.0/8", "172.16.0.0/12", "192.168.0.0/16")]

Threat mappingedit

Framework: MITRE ATT&CKTM

Rule version historyedit

Version 5 (7.12.0 release)
  • Formatting only
Version 4 (7.10.0 release)
  • Updated query, changed from:

    event.category:network and event.type:connection and
    process.name:certutil.exe and not destination.ip:(10.0.0.0/8 or
    172.16.0.0/12 or 192.168.0.0/16)
Version 3 (7.9.1 release)
  • Formatting only
Version 2 (7.9.0 release)
  • Updated query, changed from:

    process.name:certutil.exe and event.action:"Network connection
    detected (rule: NetworkConnect)" and not destination.ip:(10.0.0.0/8 or
    172.16.0.0/12 or 192.168.0.0/16)