Creation or Modification of Root Certificate

Elastic Stack Serverless Security

Identifies the creation or modification of a local trusted root certificate in Windows. The installation of a malicious root certificate would allow an attacker the ability to masquerade malicious files as valid signed components from any entity (for example, Microsoft). It could also allow an attacker to decrypt SSL traffic.

Rule type: eql

Rule indices:

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

Severity: low

Risk score: 21

Runs every: 5m

Searches indices from: now-9m (https://www.elastic.co/guide/en/elasticsearch/reference/current/common-options.html#date-math[Date Math format], see also Additional look-back time)

Maximum alerts per execution: 100

References:

• https://posts.specterops.io/code-signing-certificate-cloning-attacks-and-defenses-6f98657fc6ec
• https://www.ired.team/offensive-security/persistence/t1130-install-root-certificate

Tags:

• Elastic
• Host
• Windows
• Threat Detection
• Defense Evasion

Version: 2

Rule authors:

• Elastic

Rule license: Elastic License v2

If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2, events will not define event.ingested and default fallback for EQL rules was not added until 8.2, so you will need to add a custom pipeline to populate event.ingested to @timestamp for this rule to work.

registry where event.type in ("creation", "change") and
  registry.path :
    (
      "HKLM\\Software\\Microsoft\\SystemCertificates\\Root\\Certificates\\*\\Blob",
      "HKLM\\Software\\Microsoft\\SystemCertificates\\AuthRoot\\Certificates\\*\\Blob",
      "HKLM\\Software\\Policies\\Microsoft\\SystemCertificates\\Root\\Certificates\\*\\Blob",
      "HKLM\\Software\\Policies\\Microsoft\\SystemCertificates\\AuthRoot\\Certificates\\*\\Blob"
    )

Framework: MITRE ATT&CKTM

• Tactic:

  • Name: Defense Evasion
  • ID: TA0005
  • Reference URL: https://attack.mitre.org/tactics/TA0005/

• Technique:

  • Name: Subvert Trust Controls
  • ID: T1553
  • Reference URL: https://attack.mitre.org/techniques/T1553/

• Sub-technique:

  • Name: Install Root Certificate
  • ID: T1553.004
  • Reference URL: https://attack.mitre.org/techniques/T1553/004/