UtilityFunctions.ps1 Proxy Dll

Hunt Hypothesis

Detects the use of a Microsoft signed script executing a managed DLL with PowerShell.

Detection Rule

Sigma (Original)

title: UtilityFunctions.ps1 Proxy Dll
id: 0403d67d-6227-4ea8-8145-4e72db7da120
status: test
description: Detects the use of a Microsoft signed script executing a managed DLL with PowerShell.
references:
    - https://lolbas-project.github.io/lolbas/Scripts/UtilityFunctions/
author: frack113
date: 2022-05-28
tags:
    - attack.stealth
    - attack.t1216
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        CommandLine|contains:
            - 'UtilityFunctions.ps1'
            - 'RegSnapin '
    condition: selection
falsepositives:
    - Unknown
level: medium

KQL (Azure Sentinel)

imProcessCreate
| where TargetProcessCommandLine contains "UtilityFunctions.ps1" or TargetProcessCommandLine contains "RegSnapin "

Required Data Sources

False Positive Guidance

• Unknown

MITRE ATT&CK Context

• Technique: T1216 — T1216

References

• https://lolbas-project.github.io/lolbas/Scripts/UtilityFunctions/
• SigmaHQ Rule