Detection rules › Sigma
Dllhost.EXE Execution Anomaly
Detects a "dllhost" process spawning with no commandline arguments which is very rare to happen and could indicate process injection activity or malware mimicking similar system processes.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Privilege Escalation | T1055 Process Injection |
| Stealth | T1055 Process Injection |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
| Security-Auditing | Event ID 4688 | A new process has been created. |
Rule body yaml
title: Dllhost.EXE Execution Anomaly
id: e7888eb1-13b0-4616-bd99-4bc0c2b054b9
status: test
description: Detects a "dllhost" process spawning with no commandline arguments which is very rare to happen and could indicate process injection activity or malware mimicking similar system processes.
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
author: Nasreddine Bencherchali (Nextron Systems)
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
Stages and Predicates
Stage 0: condition
selection and not 1 of filter_main_*Stage 1: selection
selection:
Image|endswith: '\dllhost.exe'
CommandLine:
- 'dllhost.exe'
- 'dllhost'
Stage 2: not filter_main_null
filter_main_null:
CommandLine: null
Exclusions
Top-level NOT(...) conjuncts: predicates this rule actively suppresses.
| Field | Kind | Excluded values |
|---|---|---|
CommandLine | is_null |
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
CommandLine | eq |
|
Image | ends_with |
|