Malicious Regsvr32 Scriptlet or Remote COM Object Execution (via process_creation)

ATT&CK techniques

Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
- T1218.010Regsvr32
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects regsvr32.exe registering a scriptlet through scrobj.dll or loading a COM object from a remote URL, the "Squiblydoo" proxy-execution pattern. Regsvr32 is a recurring System Binary Proxy Execution technique in the Red Canary Threat Detection Report, abused to run attacker script code under a signed Microsoft binary while bypassing application allowlisting. Detecting the scrobj and remote-URL invocations flags the evasion.

Reporting behind it

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

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

Malicious regsvr32 Scriptlet Execution via scrobj.dll

Malicious Regsvr32 Scriptlet or Remote COM Object Execution (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.

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