Detection rules › Sigma

WMI module loaded by suspicious process

Status
experimental
Severity
high
Log source
product windows, service image_loaded
Author
shortly adapted from Roberto Rodriguez rule
Source
github.com/mdecrevoisier/SIGMA-detection-rules

Detects scenarios where an attacker attempts to load WMI modules from a suspicious process (like PowerShell).

MITRE ATT&CK coverage

Rule body yaml

title: WMI module loaded by suspicious process
description: Detects scenarios where an attacker attempts to load WMI modules from a suspicious process (like PowerShell).
references:
- https://github.com/mdecrevoisier/EVTX-to-MITRE-Attack/tree/master/TA0002-Execution/T1047-Windows%20Management%20Instrumentation
- https://threathunterplaybook.com/notebooks/windows/02_execution/WIN-190811201010.html
- https://medium.com/threatpunter/detecting-adversary-tradecraft-with-image-load-event-logging-and-eql-8de93338c16
- https://medium.com/threatpunter/detecting-adversary-tradecraft-with-image-load-event-logging-and-eql-8de93338c16
- https://posts.specterops.io/real-time-sysmon-processing-via-ksql-and-helk-part-3-basic-use-case-8fbf383cb54f
- https://github.com/OTRF/ThreatHunter-Playbook/blob/master/signatures/sigma/sysmon_wmi_module_load.yml
- https://www.darkoperator.com/blog/2017/10/14/basics-of-tracking-wmi-activity
tags:
- attack.execution
- attack.t1047
author: shortly adapted from Roberto Rodriguez rule
status: experimental
logsource:
  product: windows
  service: image_loaded
detection:
  selection:
    EventID: 7 # image loaded
    ImageLoaded|endswith:
      - '\wmiclnt.dll'
      - '\WmiApRpl.dll'
      - '\wmiprov.dll'
      - '\wmiutils.dll'
      - '\wbemcomn.dll'
      - '\WMINet_Utils.dll'
      - '\wbemsvc.dll'
      - '\fastprox.dll'
      - '\wmi*'
  filter:
    Image|endswith:
      - '\wmiprvse.exe'
      - '\wmiapsrv.exe'
      - '\svchost.exe'
  condition: selection and not filter
falsepositives:
- None
level: high

Stages and Predicates

Stage 0: condition

selection and not filter

Stage 1: selection

selection:
  EventID: 7
  ImageLoaded|endswith:
    - '\wmiclnt.dll'
    - '\WmiApRpl.dll'
    - '\wmiprov.dll'
    - '\wmiutils.dll'
    - '\wbemcomn.dll'
    - '\WMINet_Utils.dll'
    - '\wbemsvc.dll'
    - '\fastprox.dll'
    - '\wmi*'

Stage 2: not filter

filter:
  Image|endswith:
    - '\wmiprvse.exe'
    - '\wmiapsrv.exe'
    - '\svchost.exe'

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
Imageends_with\svchost.exe
Imageends_with\wmiapsrv.exe
Imageends_with\wmiprvse.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.

FieldKindValues
ImageLoadedends_with
  • \WMINet_Utils.dll corpus 2 (sigma 2)
  • \WmiApRpl.dll corpus 2 (sigma 2)
  • \fastprox.dll corpus 3 (sigma 3)
  • \wbemcomn.dll corpus 3 (sigma 3)
  • \wbemsvc.dll corpus 3 (sigma 3)
  • \wmi*
  • \wmiclnt.dll corpus 3 (sigma 3)
  • \wmiprov.dll corpus 2 (sigma 2)
  • \wmiutils.dll corpus 3 (sigma 3)