Detection rules › Sigma

Uncommon Svchost Parent Process

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

Detects an uncommon svchost parent process

MITRE ATT&CK coverage

Telemetry coverage

Rule body

title: Uncommon Svchost Parent Process
id: 01d2e2a1-5f09-44f7-9fc1-24faa7479b6d
status: test
description: Detects an uncommon svchost parent process
references:
    - Internal Research
author: Florian Roth (Nextron Systems)
date: 2017-08-15
modified: 2022-06-28
tags:
    - attack.stealth
    - attack.t1036.005
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\svchost.exe'
    filter_main_generic:
        ParentImage|endswith:
            - '\Mrt.exe'
            - '\MsMpEng.exe'
            - '\ngen.exe'
            - '\rpcnet.exe'
            - '\services.exe'
            - '\TiWorker.exe'
    filter_main_parent_null:
        ParentImage: null
    filter_main_parent_empty:
        ParentImage:
            - '-'
            - ''
    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:
    Image|endswith: '\svchost.exe'

Stage 2: not filter_main_*

filter_main_generic:
    ParentImage|endswith:
        - '\Mrt.exe'
        - '\MsMpEng.exe'
        - '\ngen.exe'
        - '\rpcnet.exe'
        - '\services.exe'
        - '\TiWorker.exe'
filter_main_parent_null:
    ParentImage: null
filter_main_parent_empty:
    ParentImage:
        - '-'
        - ''

Exclusions

The rule actively suppresses these predicates.

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Imageends_with
  • \svchost.exe corpus 23 (sigma 22, kusto 1)
field:"Image" kind:ends_with value:"\svchost.exe"