Execution via WorkFolders.exe

Hunt Hypothesis

Detects using WorkFolders.exe to execute an arbitrary control.exe

Detection Rule

Sigma (Original)

title: Execution via WorkFolders.exe
id: 0bbc6369-43e3-453d-9944-cae58821c173
status: test
description: Detects using WorkFolders.exe to execute an arbitrary control.exe
references:
    - https://twitter.com/elliotkillick/status/1449812843772227588
author: Maxime Thiebaut (@0xThiebaut)
date: 2021-10-21
modified: 2022-12-25
tags:
    - attack.stealth
    - attack.t1218
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\control.exe'
        ParentImage|endswith: '\WorkFolders.exe'
    filter:
        Image: 'C:\Windows\System32\control.exe'
    condition: selection and not filter
falsepositives:
    - Legitimate usage of the uncommon Windows Work Folders feature.
level: high

KQL (Azure Sentinel)

imProcessCreate
| where (TargetProcessName endswith "\\control.exe" and (ParentProcessName endswith "\\WorkFolders.exe" or ActingProcessName endswith "\\WorkFolders.exe")) and (not(TargetProcessName =~ "C:\\Windows\\System32\\control.exe"))

Required Data Sources

False Positive Guidance

• Legitimate usage of the uncommon Windows Work Folders feature.

MITRE ATT&CK Context

• Technique: T1218 — T1218

References

• https://twitter.com/elliotkillick/status/1449812843772227588
• SigmaHQ Rule