Windows Process Creation: PowerShell Command Execution Hidden in DLL Invocation
Flags DLL-invoking Windows binaries whose command lines include PowerShell execution strings.
- Product
- windows
- Category
- process_creation
- Author
- Markus Neis, Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
- Published
- 2018-08-25
- Updated
- 2026-07-30
ATT&CK techniques
Defense EvasionRecon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule identifies Windows processes commonly abused to execute DLLs (e.g., rundll32, regsvr32, regasm, regsvcs, installutil) when their command line contains PowerShell-related strings such as DownloadString, FromBase64String, IEX, Invoke-Expression, or Invoke-Command. Attackers may pass PowerShell payloads through DLL invocation to blend in with legitimate signed binary execution paths. The detection relies on process creation telemetry, matching Image and OriginalFileName with specific DLL-related executables and inspecting the CommandLine for PowerShell command indicators.
Reporting behind it
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
title: "Windows Process Creation: PowerShell Command Execution Hidden in DLL Invocation"
id: cad4364e-f234-4f38-9862-e47e57bdca07
status: test
description: This rule identifies Windows processes commonly abused to execute DLLs (e.g., rundll32, regsvr32, regasm, regsvcs, installutil) when their command line contains PowerShell-related strings such as DownloadString, FromBase64String, IEX, Invoke-Expression, or Invoke-Command. Attackers may pass PowerShell payloads through DLL invocation to blend in with legitimate signed binary execution paths. The detection relies on process creation telemetry, matching Image and OriginalFileName with specific DLL-related executables and inspecting the CommandLine for PowerShell command indicators.
references:
- https://github.com/p3nt4/PowerShdll/blob/62cfa172fb4e1f7f4ac00ca942685baeb88ff356/README.md
- https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_susp_powershell_execution_via_dll.yml
author: Markus Neis, Nasreddine Bencherchali (Nextron Systems), Huntrule Team
date: 2018-08-25
modified: 2024-03-07
tags:
- attack.stealth
- attack.t1218.011
logsource:
category: process_creation
product: windows
detection:
selection_img:
- Image|endswith:
- \InstallUtil.exe
- \RegAsm.exe
- \RegSvcs.exe
- \regsvr32.exe
- \rundll32.exe
- OriginalFileName:
- InstallUtil.exe
- RegAsm.exe
- RegSvcs.exe
- REGSVR32.EXE
- RUNDLL32.EXE
selection_cli:
CommandLine|contains:
- Default.GetString
- DownloadString
- FromBase64String
- "ICM "
- "IEX "
- Invoke-Command
- Invoke-Expression
condition: all of selection_*
falsepositives:
- Unknown
level: high
license: DRL-1.1
related:
- id: 6812a10b-60ea-420c-832f-dfcc33b646ba
type: derived