huntrule

Windows rundll32.exe executing InstallScreenSaver via desk.cpl SCR File

Detects rundll32.exe launches with InstallScreenSaver behavior via desk.cpl, a screensaver execution technique.

FreeReviewedSigma · Medium · v1
Product
windows
Category
process_creation
Author
Christopher Peacock @securepeacock, SCYTHE @scythe_io, TactiKoolSec (SigmaHQ), DRL 1.1
Published
2022-04-28
Updated
2026-07-30
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 invoked with a command line containing InstallScreenSaver, consistent with launching a screensaver (desk.cpl) execution path. Attackers use this technique to blend execution into normal-looking desktop component activity while loading functionality through rundll32. It relies on Windows process creation telemetry, specifically the executable image/original filename and the command line content.

Reporting behind it

Related detections9 linkedT1218.011 — drag to rearrange
Malicious Zardoor Backdoor Execution via rundll32 (via process_creation)
Malicious Rundll32 Loading an Export From a User Path (via process_creation)
Renamed Regsvr32 or Rundll32 Loading a DLL With a Non-Standard Extension (via process_creation)
Malicious Rundll32 DllRegisterServer Execution From a User-Writable Path (via process_creation)
IMEEX Framework DLL Execution via Rundll32 Loading imaadp (via process_creation)
Suspicious Persistence via pcalua Launching rundll32 Control_RunDLL
Suspicious Rundll32 Executing DLL Start Export With Control Flags
Suspicious Rundll32 Execution of Timestamp-Named DLL
Suspicious Rundll32 Loading DLL from LocalAppData with Short Export (via process_creation)
Windows rundll32.exe executing InstallScreenSaver via desk.cpl SCR File
Pivot detection · T1218.011 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.