Windows Process Creation: wfc.exe Execution for Workflow Command-line Compiler Abuse

Alerts on execution of wfc.exe by matching process image and OriginalFileName in Windows process creation logs.

FreeUnreviewedSigmamediumv1

windows-process-creation-wfc-exe-execution-for-workflow-command-line-compiler-ab-49be8799

title: "Windows Process Creation: wfc.exe Execution for Workflow Command-line Compiler Abuse"
id: 042a3a29-8353-4d2a-b85f-61ff663c4bf7
status: test
description: This rule flags process creation events where the executed binary is wfc.exe, identified by filename and OriginalFileName. wfc.exe can be abused to execute actions under the guise of a legitimate Windows workflow-related compiler component, which may help attackers blend in with normal software activity. It relies on process creation telemetry containing the process image path and the OriginalFileName field.
references:
  - https://lolbas-project.github.io/lolbas/OtherMSBinaries/Wfc/
  - https://learn.microsoft.com/en-us/windows/security/application-security/application-control/windows-defender-application-control/design/applications-that-can-bypass-wdac
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_lolbin_wfc.yml
author: Christopher Peacock @SecurePeacock, SCYTHE @scythe_io, Huntrule Team
date: 2022-06-01
tags:
  - attack.execution
  - attack.stealth
  - attack.t1127
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    - Image|endswith: \wfc.exe
    - OriginalFileName: wfc.exe
  condition: selection
falsepositives:
  - Legitimate use by a software developer
level: medium
license: DRL-1.1
related:
  - id: 49be8799-7b4d-4fda-ad23-cafbefdebbc5
    type: derived

What it detects

This rule flags process creation events where the executed binary is wfc.exe, identified by filename and OriginalFileName. wfc.exe can be abused to execute actions under the guise of a legitimate Windows workflow-related compiler component, which may help attackers blend in with normal software activity. It relies on process creation telemetry containing the process image path and the OriginalFileName field.

Known false positives

Legitimate use by a software developer

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.