Image Loaded with Invalid Signature

Identifies binaries that are loaded and with an invalid code signature. This may indicate an attempt to masquerade as a signed binary.

Rule type: eql
Rule indices:

• logs-endpoint.events.library-*

Rule Severity: low
Risk Score: 21
Runs every: 60m
Searches indices from: now-119m
Maximum alerts per execution: ?
References:

Tags:

• Domain: Endpoint
• OS: Windows
• Use Case: Threat Detection
• Tactic: Defense Evasion
• Rule Type: BBR
• Data Source: Elastic Defend

Version: ?
Rule authors:

• Elastic

Rule license: Elastic License v2

library where host.os.type == "windows" and event.action == "load" and
  dll.code_signature.status : ("errorUntrustedRoot", "errorBadDigest", "errorUntrustedRoot") and
  (dll.Ext.relative_file_creation_time <= 500 or dll.Ext.relative_file_name_modify_time <= 500) and
  not startswith~(dll.name, process.name) and
  not dll.path : (
    "?:\\Windows\\System32\\DriverStore\\FileRepository\\*"
  )

Framework: MITRE ATT&CK

• Tactic:

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

• Technique:

  • Name: Masquerading
  • Id: T1036
  • Reference URL: https://attack.mitre.org/techniques/T1036/

• Sub Technique:

  • Name: Invalid Code Signature
  • Id: T1036.001
  • Reference URL: https://attack.mitre.org/techniques/T1036/001/