Windows MSIExec Unregister DLLRegisterServer
The following analytic detects the use of msiexec.exe with the /z switch parameter, which is used to unload DLLRegisterServer. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing…
Description
The following analytic detects the use of msiexec.exe with the /z switch parameter, which is used to unload DLLRegisterServer. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs, including command-line arguments. This activity is significant because unloading DLLRegisterServer can be indicative of an attempt to deregister a DLL, potentially disrupting legitimate services or hiding malicious activity. If confirmed malicious, this could allow an attacker to disable security controls, evade detection, or disrupt system functionality, leading to further compromise of the environment.
Detection logic
Detection requirements
- Platform
- Windows
The rule states no platform. This is derived from the ATT&CK technique it maps to.
- Log source category
- crowdstrike_processrollup2sysmon_eventid_1windows_event_log_security_4688
Known benign triggers
- This analytic will need to be tuned for your environment based on legitimate usage of msiexec.exe. Filter as needed.
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| github.com/redcanaryco/atomic-red-team/blob/388942adbd9641f4dfdcf079d7efe9a75ec0ac43/atomics/T1218.007/T1218.007.yaml#L281 | 4 |
| github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1218.007/T1218.007.md | 5 |
| thedfirreport.com/2022/06/06/will-the-real-msiexec-please-stand-up-exploit-leads-to-data-exfiltration/ | 8from 2 sources |
From the source
- At source
- Open at source
- Upstream identifier
- a27db3c5-1a9a-46df-a577-765d3f1a3c24
- Tagged by the source as
- Windows System Binary Proxy Execution MSIExecEndpointendpointSplunk CloudSplunk EnterpriseSplunk Enterprise Securityendpoint
Licence
- Published under
- Apache License 2.0Read the licence
- Attribution
- Required
- Obtained under
- Apache-2.0Read the origin licence
Authorship
- Written by
- Published
- Oct 13, 2026
- Version
- 2