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Windows Process Creation: Suspicious Child Processes Spawned by regsvr32.exe

Alerts when regsvr32.exe spawns suspicious child processes like PowerShell, mshta, or scripting utilities.

FreeReviewedSigma · High · v1
Product
windows
Category
process_creation
Author
elhoim, Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2022-05-05
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 events where the parent process is regsvr32.exe and the child process image matches a set of common interactive or scripting tools. Such behavior matters because regsvr32.exe can be abused to load and execute code via child processes, blending execution into normal-looking Windows activity. The detection relies on Windows process creation telemetry, specifically parent image and child image (with an exclusion for werfault.exe launched with a particular command-line pattern).

Reporting behind it

Related detections9 linkedT1218.010 — drag to rearrange
Malicious DLL Registration via regsvr32 Loading prnfldr (via process_creation)
Suspicious Regsvr32 Execution of SafePay Loader DLL
Suspicious Scheduled Task Running Regsvr32 with Extreme Duration by StaryDobry
Malicious DynamicWrapperX Registration via regsvr32 (via process_creation)
Suspicious Run Key Persistence Executing regsvr32
Suspicious regsvr32 Registering DLL from User AppData
Malicious Regsvr32 Loading Masqueraded VPN DLL via Process Creation
Malicious Regsvr32 ShellExec_RunDLL Proxy Execution (via process_creation)
Suspicious DLL Execution via Regsvr32 DllInstall of dat File
Windows Process Creation: Suspicious Child Processes Spawned by regsvr32.exe
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.