Windows dllhost.exe Launched With No Command-Line Arguments

Alerts on dllhost.exe being executed with no command-line arguments, a rare pattern that may indicate stealthy or injected activity.

FreeReviewedSigma · High · v2
Product
windows
Category
process_creation
Author
Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2022-06-27
Updated
2026-07-31
title: Windows dllhost.exe Launched With No Command-Line Arguments
id: 41e8550b-52ee-443f-81a4-b6ec0861b2dc
status: test
description: This rule flags process creation where the executable name ends with \dllhost.exe and the observed command line is either exactly "dllhost.exe" or "dllhost" with no additional arguments. Because dllhost is typically launched with specific parameters, this unusual process invocation can indicate stealthy behavior such as process injection or malware masquerading as a legitimate system component. It relies on Windows process creation telemetry, including Image and CommandLine fields, and filters out events where the CommandLine value is null.
references:
  - https://redcanary.com/blog/child-processes/
  - https://nasbench.medium.com/what-is-the-dllhost-exe-process-actually-running-ef9fe4c19c08
  - https://www.ncsc.gov.uk/static-assets/documents/malware-analysis-reports/goofy-guineapig/NCSC-MAR-Goofy-Guineapig.pdf
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_dllhost_no_cli_execution.yml
author: Nasreddine Bencherchali (Nextron Systems), Huntrule Team
date: 2022-06-27
modified: 2023-05-15
tags:
  - attack.privilege-escalation
  - attack.stealth
  - attack.t1055
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    Image|endswith: \dllhost.exe
    CommandLine:
      - dllhost.exe
      - dllhost
  filter_main_null:
    CommandLine: null
  condition: selection and not 1 of filter_main_*
falsepositives:
  - Unlikely
level: high
license: DRL-1.1
related:
  - id: e7888eb1-13b0-4616-bd99-4bc0c2b054b9
    type: derived