HttpSpy Payload Registration via Regsvr32 of Non-DLL File (via process_creation)

PremiumReviewedSigma · High · v1
Product
windows
Category
process_creation
Author
HuntRule
Published
2026-08-22
Updated
2026-08-28

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 detects regsvr32.exe silently registering a payload with a data or non standard extension staged in ProgramData or the public users directory, the loader behavior of the Kimsuky HttpSpy variant that hides its spyLoader DLL as cacheMon.dat and mTSTCv8.mdxm. Adversaries leverage regsvr32 as a signed proxy to execute a disguised DLL while evading extension based controls, making early detection critical for catching the loader before the HttpSpy main module runs.

Related detections9 linkedT1218.010 — drag to rearrange
Malicious Regsvr32 ShellExec_RunDLL Proxy Execution (via process_creation)
Suspicious DLL Execution via Regsvr32 DllInstall of dat File
Malicious Xctdoor XcLoader Execution via Regsvr32 AppX Path Abuse (via process_creation)
Malicious Office Application Loading a User-Path DLL via Regsvr32 or Rundll32 (via process_creation)
Masquerading SSLoad PhantomLoader DLL Execution via Regsvr32 Silent Load from AppData (via process_creation)
Malicious Kimsuky AlphaSeed Payload Execution via Regsvr32 Loading edge dat (via process_creation)
Malicious Regsvr32 Executing DLL From Windows Temp
Malicious regsvr32 Scriptlet Execution via scrobj.dll
Suspicious Regsvr32 Squiblydoo Remote Scriptlet Execution via Command Line (via process_creation)
HttpSpy Payload Registration via Regsvr32 of Non-DLL File (via process_creation)
Pivot detection · T1218.010 · 9 related

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