huntrule

Windows: Rundll32 Launching NSIS Module for Stealer Capability

Alerts on rundll32.exe execution tied to NSIS module loading indicators (nsis_uns and PrintUIEntry) in the command line.

FreeReviewedSigma · Medium · v5
Product
windows
Category
process_creation
Author
TropChaud (SigmaHQ), DRL 1.1
Published
2023-01-26
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

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 process creation where Rundll32.EXE is used to load a module associated with an NSIS artifact, indicated by the presence of specific NSIS-related and export-function strings in the command line. Attackers often use Rundll32 to blend malicious DLL/module execution into legitimate Windows behavior. Detection relies on Windows process creation telemetry including the OriginalFileName and command-line arguments.

Reporting behind it

Related detections9 linkedT1218.011 — drag to rearrange
Malicious Lunar Spider Loader Execution via rundll32 (via process_creation)
Malicious SYSTEM Persistence via Scheduled Task Running rundll32 at Startup (via process_creation)
Malicious Rundll32 Executing Image File as DLL
Suspicious Scheduled Task Executing Rundll32 DLL Export by Ordinal
Malicious Renamed Rundll32 Copied to Temp via Xcopy
Suspicious rundll32 Executing DLL from ProgramData (via process_creation)
Suspicious Rundll32 Loading DLL From Public or ProgramData Path via Process Creation (via process_creation)
Malicious LSASS Credential Dump via Rundll32 Comsvcs MiniDump via Process Creation (via process_creation)
Suspicious Rundll32 Execution Without a DLL Reference via Process Creation (via process_creation)
Windows: Rundll32 Launching NSIS Module for Stealer Capability
Pivot detection · T1218.011 · 9 related

Changelog

v5
  1. v5
    Candidate ingested via manual entry.2026-07-31
  2. v4
    Candidate ingested via manual entry.2026-07-31
  3. v3
    Candidate ingested via manual entry.2026-07-31
  4. v2
    Candidate ingested via manual entry.2026-07-31
  5. 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.