Detection rules › Sigma

Suspicious Rundll32 Invoking Inline VBScript

Status
test
Severity
high
Log source
product windows, category process_creation
Author
Florian Roth (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects suspicious process related to rundll32 based on command line that invokes inline VBScript as seen being used by UNC2452

MITRE ATT&CK coverage

TacticTechniques
Privilege EscalationT1055 Process Injection
StealthT1055 Process Injection

Event coverage

Rule body yaml

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

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    CommandLine|contains|all:
        - 'rundll32.exe'
        - 'Execute'
        - 'RegRead'
        - 'window.close'

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
CommandLinematch
  • Execute corpus 5 (kusto 3, sigma 2)
  • RegRead corpus 5 (kusto 3, sigma 2)
  • rundll32.exe corpus 8 (sigma 8)
  • window.close corpus 5 (kusto 3, sigma 2)