Code Execution via Pcwutl.dll

Status: test
Severity: medium
Log source: category process_creation, product windows
Author: Julia Fomina, oscd.community
Source: github.com/SigmaHQ/sigma

Detects launch of executable by calling the LaunchApplication function from pcwutl.dll library.

Known false positives

Use of Program Compatibility Troubleshooter Helper

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1218.011` System Binary Proxy Execution: Rundll32

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation

Rule body

title: Code Execution via Pcwutl.dll
id: 9386d78a-7207-4048-9c9f-a93a7c2d1c05
status: test
description: Detects launch of executable by calling the LaunchApplication function from pcwutl.dll library.
references:
    - https://lolbas-project.github.io/lolbas/Libraries/Pcwutl/
    - https://twitter.com/harr0ey/status/989617817849876488
author: Julia Fomina, oscd.community
date: 2020-10-05
modified: 2023-02-09
tags:
    - attack.stealth
    - attack.t1218.011
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\rundll32.exe'
        - OriginalFileName: 'RUNDLL32.EXE'
    selection_cli:
        CommandLine|contains|all:
            - 'pcwutl'
            - 'LaunchApplication'
    condition: all of selection_*
falsepositives:
    - Use of Program Compatibility Troubleshooter Helper
level: medium

Stages and Predicates

Stage 0: `condition`

all of selection_*

Stage 1: `selection_img`

selection_img:
    - Image|endswith: '\rundll32.exe'
    - OriginalFileName: 'RUNDLL32.EXE'

Stage 2: `selection_cli`

selection_cli:
    CommandLine|contains|all:
        - 'pcwutl'
        - 'LaunchApplication'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`CommandLine`	match	`LaunchApplication` corpus 2 (sigma 2) `pcwutl`	`field:"CommandLine" kind:match`
`Image`	ends_with	`\rundll32.exe` corpus 94 (sigma 94)	`field:"Image" kind:ends_with value:"\rundll32.exe"`
`OriginalFileName`	eq	`RUNDLL32.EXE` corpus 78 (sigma 35, elastic 22, splunk 21)	`field:"OriginalFileName" kind:eq value:"RUNDLL32.EXE"`

Code Execution via Pcwutl.dll

Known false positives

MITRE ATT&CK coverage

Telemetry coverage

Rule body

Stages and Predicates

Stage 0: condition

Stage 1: selection_img

Stage 2: selection_cli

Indicators

Stage 0: `condition`

Stage 1: `selection_img`

Stage 2: `selection_cli`