WMI registration (PowerShell)

Status: experimental
Severity: high
Log source: category ['ps_module', 'ps_classic_script', 'ps_script'], product windows
Author: mdecrevoisier
Source: github.com/mdecrevoisier/SIGMA-detection-rules

Detects scenarios where an attacker createsan instance of a WMI class using tools like WMImplant or PowerLurk.

Known false positives

legitimate WMI class registration
monitoring products
Microsoft System Center or security products

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1546.003` Event Triggered Execution: Windows Management Instrumentation Event Subscription

Telemetry coverage

Provider	Record / event type
PowerShell	Event ID 4103: Payload Context: ContextInfo User Data: UserData.
PowerShell	Event ID 4104: Creating Scriptblock text (MessageNumber of MessageTotal).
PowerShell	Event ID 800

Rule body

title: WMI registration (PowerShell)
description: Detects scenarios where an attacker createsan instance of a WMI class using tools like WMImplant or PowerLurk.
references:
- https://github.com/mdecrevoisier/EVTX-to-MITRE-Attack/tree/master/TA0003-Persistence/T1546-Event%20Triggered%20Execution
- https://github.com/Sw4mpf0x/PowerLurk
- https://github.com/FortyNorthSecurity/WMImplant
- https://www.netspi.com/blog/technical/adversary-simulation/getting-started-wmi-weaponization-part-5/
- https://www.darkoperator.com/blog/2017/10/14/basics-of-tracking-wmi-activity
tags:
- attack.persistence
- attack.t1546.003
author: mdecrevoisier
status: experimental
logsource:
  product: windows
  category:
    - ps_module
    - ps_classic_script
    - ps_script

detection:
  selection1_powershell_native:
    EventID: 800
    EventData|contains:
      - Set-WmiInstance
      - Swmi
    EventData|contains:
      - Class
      - Namespace
      - Arguments

  selection2_powershell_modern:
    EventID: 4103
    Payload|contains:
      - Set-WmiInstance
      - Swmi
    Payload|contains:
      - Class
      - Namespace
      - Arguments

  selection3_powershell_block:
    EventID: 4104
    ScriptBlockText|contains:
      - Set-WmiInstance
      - Swmi
    ScriptBlockText|contains:
      - Class
      - Namespace
      - Arguments

  condition: 1 of selection*
falsepositives:
- legitimate WMI class registration
- monitoring products
- Microsoft System Center or security products
level: high

Stages and Predicates

Stage 0: `condition`

1 of selection*

Stage 1: `selection1_powershell_native`

selection1_powershell_native:
  EventID: 800
  EventData|contains:
    - Set-WmiInstance
    - Swmi
  EventData|contains:
    - Class
    - Namespace
    - Arguments

Stage 2: `selection2_powershell_modern`

selection2_powershell_modern:
  EventID: 4103
  Payload|contains:
    - Set-WmiInstance
    - Swmi
  Payload|contains:
    - Class
    - Namespace
    - Arguments

Stage 3: `selection3_powershell_block`

selection3_powershell_block:
  EventID: 4104
  ScriptBlockText|contains:
    - Set-WmiInstance
    - Swmi
  ScriptBlockText|contains:
    - Class
    - Namespace
    - Arguments

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`EventData`	match	`Arguments` `Class` `Namespace`	`field:"EventData" kind:match`
`Payload`	match	`Arguments` `Class` `Namespace`	`field:"Payload" kind:match`
`ScriptBlockText`	match	`Arguments` `Class` `Namespace`	`field:"ScriptBlockText" kind:match`

WMI registration (PowerShell)

Known false positives

MITRE ATT&CK coverage

Telemetry coverage

Rule body

Stages and Predicates

Stage 0: condition

Stage 1: selection1_powershell_native

Stage 2: selection2_powershell_modern

Stage 3: selection3_powershell_block

Indicators

Stage 0: `condition`

Stage 1: `selection1_powershell_native`

Stage 2: `selection2_powershell_modern`

Stage 3: `selection3_powershell_block`