Detect Regsvr32 Application Control Bypass
The following analytic identifies the abuse of Regsvr32.exe to proxy execution of malicious code, specifically detecting the loading of "scrobj.dll" by Regsvr32.exe. This detection leverages data from Endpoint…
Description
The following analytic identifies the abuse of Regsvr32.exe to proxy execution of malicious code, specifically detecting the loading of "scrobj.dll" by Regsvr32.exe. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process creation events and command-line executions. This activity is significant because Regsvr32.exe is a trusted, signed Microsoft binary, often used in "Squiblydoo" attacks to bypass application control mechanisms. If confirmed malicious, this technique could allow an attacker to execute arbitrary code, potentially leading to system compromise and persistent access.
Detection logic
Detection requirements
- Platform
- Windows
The rule states no platform. This is derived from the ATT&CK technique it maps to.
- Log source category
- crowdstrike_processrollup2sysmon_eventid_1windows_event_log_security_4688
Known benign triggers
- Limited false positives related to third party software registering .DLL's.
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| attack.mitre.org/techniques/T1218/010/ | 3 |
| github.com/redcanaryco/atomic-red-team/blob/388942adbd9641f4dfdcf079d7efe9a75ec0ac43/atomics/T1218.010/T1218.010.yaml#L38 | 2 |
| github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1218.010/T1218.010.md | 2 |
| lolbas-project.github.io/lolbas/Binaries/Regsvr32/ | 4from 2 sources |
| support.microsoft.com/en-us/topic/how-to-use-the-regsvr32-tool-and-troubleshoot-regsvr32-error-messages-a98d960a-7392-e6fe-d90a-3f4e0cb543e5 | 2 |
From the source
- At source
- Open at source
- Upstream identifier
- 070e9b80-6252-11eb-ae93-0242ac130002
- Tagged by the source as
- BlackByte RansomwareCobalt StrikeCompromised Windows HostGraceful Wipe Out AttackLiving Off The LandPHP-CGI RCE Attack on Japanese OrganizationsSuspicious Regsvr32 ActivityEndpointendpointSplunk CloudSplunk EnterpriseSplunk Enterprise Securityendpoint
Licence
- Published under
- Apache License 2.0Read the licence
- Attribution
- Required
- Obtained under
- Apache-2.0Read the origin licence
Authorship
- Written by
- Published
- Oct 13, 2026
- Version
- 2