Sigma rule: Scripting/CommandLine Process Spawned Regsvr32

Rule

Title

Scripting/CommandLine Process Spawned Regsvr32

Status

test

Level

medium

Author

Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)

Date

2023-05-26

File

rules/windows/process_creation/proc_creation_win_regsvr32_susp_parent.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects various command line and scripting engines/processes such as "PowerShell", "Wscript", "Cmd", etc. spawning a "regsvr32" instance.

Log source

product

windows

category

process_creation

Detection

selection:
    ParentImage|endswith:
        - '\cmd.exe'
        - '\cscript.exe'
        - '\mshta.exe'
        - '\powershell_ise.exe'
        - '\powershell.exe'
        - '\pwsh.exe'
        - '\wscript.exe'
    Image|endswith: '\regsvr32.exe'
filter_main_rpcproxy:
    ParentImage: C:\Windows\System32\cmd.exe
    CommandLine|endswith: ' /s C:\Windows\System32\RpcProxy\RpcProxy.dll'
condition: selection and not 1 of filter_main_*

False positives (as the rule lists them)

• Legitimate ".bat", ".hta", ".ps1" or ".vbs" scripts leverage legitimately often. Apply additional filter and exclusions as necessary
• Some legitimate Windows services

Tags

• attack.stealth
• attack.t1218.010

MITRE ATT&CK ids this rule names

• T1218.010

Related rules

• 8e2b24c9-4add-46a0-b4bb-0057b4e6187d (obsolete)

References

• https://web.archive.org/web/20171001085340/https://subt0x10.blogspot.com/2017/04/bypass-application-whitelisting-script.html
• https://app.any.run/tasks/34221348-072d-4b70-93f3-aa71f6ebecad/

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_regsvr32_susp_parent.yml