Windows Security 4697: Obfuscated command uses rundll32 with shell32.dll
Alerts on EventID 4697 service command lines containing rundll32 with shell32.dll/shellexec_rundll and obfuscation-like script fragments.
- Product
- windows
- Service
- security
- Author
- Nikita Nazarov, oscd.community (SigmaHQ), DRL 1.1
- Published
- 2020-10-09
- Updated
- 2026-07-31
ATT&CK techniques
Execution → 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 Windows Security audit events (EventID 4697) where the registered service command line contains an obfuscation pattern along with rundll32 usage of shell32.dll and related rundll export strings. Attackers may use this execution path to hide their true intent while launching script-related commands. It relies on the Security log capturing the service installation details, specifically the ServiceFileName content.
Reporting behind it
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 Security 4697: Obfuscated command uses rundll32 with shell32.dll"
id: 97206b77-2044-4435-8625-8cf96eda4949
related:
- id: 641a4bfb-c017-44f7-800c-2aee0184ce9b
type: derived
- id: cd0f7229-d16f-42de-8fe3-fba365fbcb3a
type: derived
status: test
description: This rule flags Windows Security audit events (EventID 4697) where the registered service command line contains an obfuscation pattern along with rundll32 usage of shell32.dll and related rundll export strings. Attackers may use this execution path to hide their true intent while launching script-related commands. It relies on the Security log capturing the service installation details, specifically the ServiceFileName content.
references:
- https://github.com/SigmaHQ/sigma/issues/1009
- https://github.com/SigmaHQ/sigma/blob/master/rules/windows/builtin/security/win_security_invoke_obfuscation_via_use_rundll32_services_security.yml
author: Nikita Nazarov, oscd.community, Huntrule Team
date: 2020-10-09
modified: 2022-11-29
tags:
- attack.stealth
- attack.t1027
- attack.execution
- attack.t1059.001
logsource:
product: windows
service: security
definition: The 'System Security Extension' audit subcategory need to be enabled to log the EID 4697
detection:
selection:
EventID: 4697
ServiceFileName|contains|all:
- "&&"
- rundll32
- shell32.dll
- shellexec_rundll
ServiceFileName|contains:
- value
- invoke
- comspec
- iex
condition: selection
falsepositives:
- Unknown
level: high
license: DRL-1.1