huntrule

Windows Rundll32 Loads DLL Export StartNodeRelay (F-Secure C3)

Flags rundll32.exe launching a DLL that references the StartNodeRelay export in its command line.

FreeReviewedSigma · Critical · v2
Product
windows
Category
process_creation
Author
Alfie Champion (ajpc500) (SigmaHQ), DRL 1.1
Published
2021-06-02
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 identifies process creation where rundll32.exe is invoked with a DLL that includes the StartNodeRelay export. Adversaries can use rundll32-based DLL loading to execute code in a way that may blend with normal Windows process behavior. The detection relies on command-line telemetry containing rundll32.exe, a referenced .dll file, and the StartNodeRelay string.

Reporting behind it

Related detections9 linkedT1218.011 — drag to rearrange
Andromeda Loader Execution via Rundll32 Desktop.ini Ordinal
Suspicious rundll32 Execution of sqlite3 DLL by Ordinal with TLB Argument
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
Windows Rundll32 Loads DLL Export StartNodeRelay (F-Secure C3)
Pivot detection · T1218.011 · 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.