Windows InstallUtil Credential Theft
The following analytic detects instances where the Windows InstallUtil.exe binary loads `vaultcli.dll` and `Samlib.dll`. This detection leverages Sysmon EventCode 7 to identify these specific DLL loads. This activity…
Description
The following analytic detects instances where the Windows InstallUtil.exe binary loads `vaultcli.dll` and `Samlib.dll`. This detection leverages Sysmon EventCode 7 to identify these specific DLL loads. This activity is significant because it can indicate an attempt to execute code that bypasses application control and captures credentials using tools like Mimikatz. If confirmed malicious, this behavior could allow an attacker to steal credentials, potentially leading to unauthorized access and further compromise of the system.
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
- Typically, this will not trigger because, by its very nature, InstallUtil does not require credentials. 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 |
|---|---|
| gist.github.com/xorrior/bbac3919ca2aef8d924bdf3b16cce3d0 | Only this detection cites it |
From the source
- At source
- Open at source
- Upstream identifier
- ccfeddec-43ec-11ec-b494-acde48001122
- Tagged by the source as
- Signed Binary Proxy Execution InstallUtilEndpointendpointSplunk 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