Detection rules › Sigma

Powershell WMI Persistence

Status
test
Severity
medium
Log source
product windows, category ps_script
Author
frack113
Source
github.com/SigmaHQ/sigma

Adversaries may establish persistence and elevate privileges by executing malicious content triggered by a Windows Management Instrumentation (WMI) event subscription.

MITRE ATT&CK coverage

Event coverage

Rule body yaml

title: Powershell WMI Persistence
id: 9e07f6e7-83aa-45c6-998e-0af26efd0a85
status: test
description: Adversaries may establish persistence and elevate privileges by executing malicious content triggered by a Windows Management Instrumentation (WMI) event subscription.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1546.003/T1546.003.md
    - https://github.com/EmpireProject/Empire/blob/08cbd274bef78243d7a8ed6443b8364acd1fc48b/data/module_source/persistence/Persistence.psm1#L545
author: frack113
date: 2021-08-19
modified: 2022-12-25
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.t1546.003
logsource:
    product: windows
    category: ps_script
    definition: 'Requirements: Script Block Logging must be enabled'
detection:
    selection_ioc:
        - ScriptBlockText|contains|all:
              - 'New-CimInstance '
              - '-Namespace root/subscription '
              - '-ClassName __EventFilter '
              - '-Property ' # is a variable name
        - ScriptBlockText|contains|all:
              - 'New-CimInstance '
              - '-Namespace root/subscription '
              - '-ClassName CommandLineEventConsumer '
              - '-Property ' # is a variable name
    condition: selection_ioc
falsepositives:
    - Unknown
level: medium

Stages and Predicates

Stage 0: condition

selection_ioc

Stage 1: selection_ioc

selection_ioc:
    - ScriptBlockText|contains|all:
          - 'New-CimInstance '
          - '-Namespace root/subscription '
          - '-ClassName __EventFilter '
          - '-Property '
    - ScriptBlockText|contains|all:
          - 'New-CimInstance '
          - '-Namespace root/subscription '
          - '-ClassName CommandLineEventConsumer '
          - '-Property '

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.

FieldKindValues
ScriptBlockTextmatch
  • -ClassName CommandLineEventConsumer
  • -ClassName __EventFilter
  • -Namespace root/subscription
  • -Property
  • New-CimInstance