Indirect Command Execution By Program Compatibility Wizard

Hunt Hypothesis

Detect indirect command execution via Program Compatibility Assistant pcwrun.exe

Detection Rule

Sigma (Original)

title: Indirect Command Execution By Program Compatibility Wizard
id: b97cd4b1-30b8-4a9d-bd72-6293928d52bc
status: test
description: Detect indirect command execution via Program Compatibility Assistant pcwrun.exe
references:
    - https://twitter.com/pabraeken/status/991335019833708544
    - https://lolbas-project.github.io/lolbas/Binaries/Pcwrun/
author: A. Sungurov , oscd.community
date: 2020-10-12
modified: 2021-11-27
tags:
    - attack.stealth
    - attack.t1218
    - attack.execution
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith: '\pcwrun.exe'
    condition: selection
falsepositives:
    - Need to use extra processing with 'unique_count' / 'filter' to focus on outliers as opposed to commonly seen artifacts
    - Legit usage of scripts
level: low

KQL (Azure Sentinel)

imProcessCreate
| where ParentProcessName endswith "\\pcwrun.exe" or ActingProcessName endswith "\\pcwrun.exe"

Required Data Sources

False Positive Guidance

• Need to use extra processing with ‘unique_count’ / ‘filter’ to focus on outliers as opposed to commonly seen artifacts
• Legit usage of scripts

MITRE ATT&CK Context

• Tactic: Execution
• Technique: T1218 — T1218

References

• https://twitter.com/pabraeken/status/991335019833708544
• https://lolbas-project.github.io/lolbas/Binaries/Pcwrun/
• SigmaHQ Rule