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.
- Product
- windows
- Category
- process_creation
- Author
- Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
- Published
- 2022-06-27
- Updated
- 2026-07-31
ATT&CK techniques
Priv Esc → 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 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.
Reporting behind it
- redcanary.comhttps://redcanary.com/blog/child-processes/
- nasbench.medium.comhttps://nasbench.medium.com/what-is-the-dllhost-exe-process-actually-running-ef9fe4c19c08
- ncsc.gov.ukhttps://www.ncsc.gov.uk/static-assets/documents/malware-analysis-reports/goofy-guineapig/NCSC-MAR-Goofy-Guineapig.pdf
- github.comhttps://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_dllhost_no_cli_execution.yml
Changelog
v2- v2Candidate ingested via manual entry.2026-07-31
- v1No 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.
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