Detection rules › Sigma

Uncommon Child Processes Of SndVol.exe

Status
test
Severity
medium
Log source
category process_creation, product windows
Author
X__Junior (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects potentially uncommon child processes of SndVol.exe (the Windows volume mixer)

MITRE ATT&CK coverage

TacticTechniques
ExecutionNo specific technique

Telemetry coverage

Rule body

title: Uncommon Child Processes Of SndVol.exe
id: ba42babc-0666-4393-a4f7-ceaf5a69191e
status: test
description: Detects potentially uncommon child processes of SndVol.exe (the Windows volume mixer)
references:
    - https://twitter.com/Max_Mal_/status/1661322732456353792
author: X__Junior (Nextron Systems)
date: 2023-06-09
tags:
    - attack.execution
logsource:
    product: windows
    category: process_creation
detection:
    selection:
        ParentImage|endswith: '\SndVol.exe'
    filter_main_rundll32:
        Image|endswith: '\rundll32.exe'
        CommandLine|contains: ' shell32.dll,Control_RunDLL '
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: medium

Stages and Predicates

Stage 0: condition

selection and not 1 of filter_main_*

Stage 1: selection

selection:
    ParentImage|endswith: '\SndVol.exe'

Stage 2: not filter_main_rundll32

filter_main_rundll32:
    Image|endswith: '\rundll32.exe'
    CommandLine|contains: ' shell32.dll,Control_RunDLL '

Exclusions

The rule actively suppresses these predicates.

FieldKindExcluded valuesSearch
CommandLinematch shell32.dll,Control_RunDLL excludes:CommandLine field:"CommandLine" value:" shell32.dll,Control_RunDLL "
Imageends_with\rundll32.exeexcludes:Image field:"Image" value:"\rundll32.exe"

Indicators

These rows show field, operator, and value matches.