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 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.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.