Detection rules › Sigma
Microsoft Workflow Compiler Execution
Detects the execution of Microsoft Workflow Compiler, which may permit the execution of arbitrary unsigned code.
Known false positives
- Legitimate MWC use (unlikely in modern enterprise environments)
MITRE ATT&CK coverage
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 1: Process creation |
Rule body
title: Microsoft Workflow Compiler Execution
id: 419dbf2b-8a9b-4bea-bf99-7544b050ec8d
status: test
description: |
Detects the execution of Microsoft Workflow Compiler, which may permit the execution of arbitrary unsigned code.
references:
- https://posts.specterops.io/arbitrary-unsigned-code-execution-vector-in-microsoft-workflow-compiler-exe-3d9294bc5efb
- https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1218/T1218.md
- https://lolbas-project.github.io/lolbas/Binaries/Microsoft.Workflow.Compiler/
author: Nik Seetharaman, frack113
date: 2019-01-16
modified: 2023-02-03
tags:
- attack.execution
- attack.stealth
- attack.t1127
- attack.t1218
- detection.threat-hunting
logsource:
category: process_creation
product: windows
detection:
selection:
- Image|endswith: '\Microsoft.Workflow.Compiler.exe'
- OriginalFileName: 'Microsoft.Workflow.Compiler.exe'
condition: selection
falsepositives:
- Legitimate MWC use (unlikely in modern enterprise environments)
level: medium
Stages and Predicates
Stage 0: condition
selectionStage 1: selection
selection:
- Image|endswith: '\Microsoft.Workflow.Compiler.exe'
- OriginalFileName: 'Microsoft.Workflow.Compiler.exe'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
Image | ends_with |
| field:"Image" kind:ends_with value:"\Microsoft.Workflow.Compiler.exe" |
OriginalFileName | eq |
| field:"OriginalFileName" kind:eq value:"Microsoft.Workflow.Compiler.exe" |