Windows Indirect Command Execution via Program Compatibility Assistant pcwrun.exe

ATT&CK techniques

Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
- T1218System Binary Proxy Execution
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule identifies process launches where the parent process is the Program Compatibility Assistant executable (pcwrun.exe). Attackers can abuse this legitimate Windows component to run commands indirectly while blending into normal execution paths. It relies on process creation telemetry, specifically the parent image path ending with \pcwrun.exe.

Reporting behind it

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Windows Indirect Command Execution via Program Compatibility Assistant pcwrun.exe

Pivot detection · T1218 · 9 related

Changelog

v2

v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

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

windows-indirect-command-execution-via-pcwrun-exe-program-compatibility-assistan-b97cd4b1

title: Windows Indirect Command Execution via Program Compatibility Assistant pcwrun.exe
id: 79d12945-b711-4028-97f2-d5e262ba9d04
status: test
description: This rule identifies process launches where the parent process is the Program Compatibility Assistant executable (pcwrun.exe). Attackers can abuse this legitimate Windows component to run commands indirectly while blending into normal execution paths. It relies on process creation telemetry, specifically the parent image path ending with \pcwrun.exe.
references:
  - https://twitter.com/pabraeken/status/991335019833708544
  - https://lolbas-project.github.io/lolbas/Binaries/Pcwrun/
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_lolbin_pcwrun.yml
author: A. Sungurov , oscd.community, Huntrule Team
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
license: DRL-1.1
related:
  - id: b97cd4b1-30b8-4a9d-bd72-6293928d52bc
    type: derived

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