Detection rules › Sigma
Potentially Suspicious Child Process Of Regsvr32
Detects potentially suspicious child processes of "regsvr32.exe".
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Stealth | T1218.010 System Binary Proxy Execution: Regsvr32 |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
| Security-Auditing | Event ID 4688 | A new process has been created. |
Rule body yaml
title: Potentially Suspicious Child Process Of Regsvr32
id: 6f0947a4-1c5e-4e0d-8ac7-53159b8f23ca
related:
- id: 8e2b24c9-4add-46a0-b4bb-0057b4e6187d
type: obsolete
status: test
description: Detects potentially suspicious child processes of "regsvr32.exe".
references:
- https://redcanary.com/blog/intelligence-insights-april-2022/
- https://www.echotrail.io/insights/search/regsvr32.exe
- https://www.ired.team/offensive-security/code-execution/t1117-regsvr32-aka-squiblydoo
author: elhoim, Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
date: 2022-05-05
modified: 2023-05-26
tags:
- attack.stealth
- attack.t1218.010
logsource:
category: process_creation
product: windows
detection:
selection:
ParentImage|endswith: '\regsvr32.exe'
Image|endswith:
- '\calc.exe'
- '\cscript.exe'
- '\explorer.exe'
- '\mshta.exe'
- '\net.exe'
- '\net1.exe'
- '\nltest.exe'
- '\notepad.exe'
- '\powershell.exe'
- '\pwsh.exe'
- '\reg.exe'
- '\schtasks.exe'
- '\werfault.exe'
- '\wscript.exe'
filter_main_werfault:
Image|endswith: '\werfault.exe'
CommandLine|contains: ' -u -p '
condition: selection and not 1 of filter_main_*
falsepositives:
- Unlikely, but can rarely occur. Apply additional filters accordingly.
level: high
Stages and Predicates
Stage 0: condition
selection and not 1 of filter_main_*Stage 1: selection
selection:
ParentImage|endswith: '\regsvr32.exe'
Image|endswith:
- '\calc.exe'
- '\cscript.exe'
- '\explorer.exe'
- '\mshta.exe'
- '\net.exe'
- '\net1.exe'
- '\nltest.exe'
- '\notepad.exe'
- '\powershell.exe'
- '\pwsh.exe'
- '\reg.exe'
- '\schtasks.exe'
- '\werfault.exe'
- '\wscript.exe'
Stage 2: not filter_main_werfault
filter_main_werfault:
Image|endswith: '\werfault.exe'
CommandLine|contains: ' -u -p '
Exclusions
Top-level NOT(...) conjuncts: predicates this rule actively suppresses.
| Field | Kind | Excluded values |
|---|---|---|
CommandLine | match | -u -p |
Image | ends_with | \werfault.exe |
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
Image | ends_with |
|
ParentImage | ends_with |
|