Suspicious Rundll32 Invoking Inline VBScript — Sigma Rule

Rule metadata and linked tags

Author: Florian Roth (Nextron Systems). Source status: test; severity: high. Source dates: 2021-03-05 / 2022-10-09.

{
  "category": "process_creation",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 2dc4317cf0ef9d3cad43cec6a32c0edb1bd02783b26219d91abeee919dcf0e0f

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Suspicious Rundll32 Invoking Inline VBScript
id: 1cc50f3f-1fc8-4acf-b2e9-6f172e1fdebd
status: test
description: Detects suspicious process related to rundll32 based on command line that invokes inline VBScript as seen being used by UNC2452
references:
    - https://www.microsoft.com/security/blog/2021/03/04/goldmax-goldfinder-sibot-analyzing-nobelium-malware/
author: Florian Roth (Nextron Systems)
date: 2021-03-05
modified: 2022-10-09
tags:
    - attack.privilege-escalation
    - attack.stealth
    - attack.t1055
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        CommandLine|contains|all:
            - 'rundll32.exe'
            - 'Execute'
            - 'RegRead'
            - 'window.close'
    condition: selection
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://www.microsoft.com/security/blog/2021/03/04/goldmax-goldfinder-sibot-analyzing-nobelium-malware/