Detection rules › Sigma

WMI ActiveScriptEventConsumers Activity Via Scrcons.EXE DLL Load

Status
test
Severity
medium
Log source
product windows, category image_load
Author
Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research)
Source
github.com/SigmaHQ/sigma

Detects signs of the WMI script host process "scrcons.exe" loading scripting DLLs which could indicates WMI ActiveScriptEventConsumers EventConsumers activity.

MITRE ATT&CK coverage

Event coverage

ProviderEventTitle
SysmonEvent ID 7Image loaded

Rule body yaml

title: WMI ActiveScriptEventConsumers Activity Via Scrcons.EXE DLL Load
id: b439f47d-ef52-4b29-9a2f-57d8a96cb6b8
status: test
description: Detects signs of the WMI script host process "scrcons.exe" loading scripting DLLs which could indicates WMI ActiveScriptEventConsumers EventConsumers activity.
references:
    - https://twitter.com/HunterPlaybook/status/1301207718355759107
    - https://www.mdsec.co.uk/2020/09/i-like-to-move-it-windows-lateral-movement-part-1-wmi-event-subscription/
    - https://threathunterplaybook.com/hunts/windows/200902-RemoteWMIActiveScriptEventConsumers/notebook.html
author: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research)
date: 2020-09-02
modified: 2023-02-22
tags:
    - attack.lateral-movement
    - attack.privilege-escalation
    - attack.persistence
    - attack.t1546.003
logsource:
    category: image_load
    product: windows
detection:
    selection:
        Image|endswith: '\scrcons.exe'
        ImageLoaded|endswith:
            - '\vbscript.dll'
            - '\wbemdisp.dll'
            - '\wshom.ocx'
            - '\scrrun.dll'
    condition: selection
falsepositives:
    - Legitimate event consumers
    - Dell computers on some versions register an event consumer that is known to cause false positives when brightness is changed by the corresponding keyboard button
level: medium

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    Image|endswith: '\scrcons.exe'
    ImageLoaded|endswith:
        - '\vbscript.dll'
        - '\wbemdisp.dll'
        - '\wshom.ocx'
        - '\scrrun.dll'

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
Imageends_with
  • \scrcons.exe corpus 9 (sigma 9)
ImageLoadedends_with
  • \scrrun.dll
  • \vbscript.dll corpus 3 (sigma 3)
  • \wbemdisp.dll
  • \wshom.ocx