MSI Module Loaded by Non-System Binary
The following analytic detects the loading of `msi.dll` by a binary not located in `system32`, `syswow64`, `winsxs`, or `windows` directories. This is identified using Sysmon EventCode 7, which logs DLL loads, and…
Description
The following analytic detects the loading of `msi.dll` by a binary not located in `system32`, `syswow64`, `winsxs`, or `windows` directories. This is identified using Sysmon EventCode 7, which logs DLL loads, and filters out legitimate system paths. This activity is significant as it may indicate exploitation of CVE-2021-41379 or DLL side-loading attacks, both of which can lead to unauthorized system modifications. If confirmed malicious, this could allow an attacker to execute arbitrary code, escalate privileges, or persist within 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
- sysmon_eventid_7
Known benign triggers
- It is possible some Administrative utilities will load msi.dll outside of normal system paths, 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 |
|---|---|
| attackerkb.com/topics/7LstI2clmF/cve-2021-41379/rapid7-analysis | Only this detection cites it |
| github.com/AlexandrVIvanov/InstallerFileTakeOver | Only this detection cites it |
| github.com/mandiant/red_team_tool_countermeasures/blob/master/rules/PGF/supplemental/hxioc/msi.dll%20Hijack%20(Methodology).ioc | Only this detection cites it |
From the source
- At source
- Open at source
- Upstream identifier
- ccb98a66-5851-11ec-b91c-acde48001122
- Tagged by the source as
- Data DestructionHermetic WiperWindows Privilege EscalationEndpointendpointSplunk 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
- Aug 26, 2026
- Version
- 1