Mofcomp Activity

edit

Managed Object Format (MOF) files can be compiled locally or remotely through mofcomp.exe. Attackers may leverage MOF files to build their own namespaces and classes into the Windows Management Instrumentation (WMI) repository, or establish persistence using WMI Event Subscription.

Rule type: eql

Rule indices:

  • logs-endpoint.events.process-*
  • logs-m365_defender.event-*
  • endgame-*
  • logs-system.security-*

Severity: low

Risk score: 21

Runs every: 5m

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

Maximum alerts per execution: 100

References: None

Tags:

  • Domain: Endpoint
  • OS: Windows
  • Use Case: Threat Detection
  • Tactic: Execution
  • Data Source: Elastic Defend
  • Data Source: Microsoft Defender for Endpoint
  • Data Source: Elastic Endgame
  • Data Source: System

Version: 3

Rule authors:

  • Elastic

Rule license: Elastic License v2

Rule query

edit
process where host.os.type == "windows" and event.type == "start" and
  process.name : "mofcomp.exe" and process.args : "*.mof" and
  not user.id : "S-1-5-18" and
  not
  (
    process.parent.name : "ScenarioEngine.exe" and
    process.args : (
      "*\\MSSQL\\Binn\\*.mof",
      "*\\Microsoft SQL Server\\???\\Shared\\*.mof",
      "*\\OLAP\\bin\\*.mof"
    )
  )

Framework: MITRE ATT&CKTM