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
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 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.