huntrule

Windows mpclient.dll Sideloading via MpCmdRun.exe or NisSrv.exe from Non-Default Paths

Alerts when mpclient.dll is loaded by MpCmdRun.exe or NisSrv.exe outside known Windows Defender directories.

FreeReviewedSigma · High · v2
Product
windows
Category
image_load
Author
Bhabesh Raj (SigmaHQ), DRL 1.1
Published
2022-08-02
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Execution → Defense Evasion

  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. C2

  13. Exfiltration

  14. Impact

What it detects

This rule flags image loads of mpclient.dll when performed by Windows Defender-related processes MpCmdRun.exe and NisSrv.exe from directories outside common, expected locations. Sideloading a DLL from an atypical path can allow an attacker to run malicious code under the context of a trusted binary, supporting persistence and stealth. It relies on Windows image load telemetry capturing the loaded DLL path and the importing process image path.

Reporting behind it

Related detections9 linkedT1574.001 — drag to rearrange
Malicious DLL Sideloading via consent.exe Loading msimg32.dll (via image_load)
Malicious Bumblebee DLL Sideload of msimg32 by consent from Non-System Path (via image_load)
Suspicious BugSplat Binary Sideloading bugsplatrc.dll via DLL Search Order Hijack
Suspicious SentinelOne Binary Sideloading sentinelagentcore.dll
Suspicious 7-Zip Executable Sideloading 7z.dll Loader
Suspicious Loading of Masqueraded EndpointDlp.dll Backdoor
Suspicious Trend Micro Binary Sideloading tmdglog.dll
Suspicious DLL Sideloading via ProtonVPN Executable (via image_load)
Suspicious DLL Sideloading via OneDriveStandaloneUpdater (via image_load)
Windows mpclient.dll Sideloading via MpCmdRun.exe or NisSrv.exe from Non-Default Paths
Pivot detection · T1574.001 · 9 related

Changelog

v2
  1. v2
    Candidate ingested via manual entry.2026-07-31
  2. v1
    No 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.