Rundll32 Execution Without Parameters

Hunt Hypothesis

Detects rundll32 execution without parameters as observed when running Metasploit windows/smb/psexec exploit module

Detection Rule

Sigma (Original)

title: Rundll32 Execution Without Parameters
id: 5bb68627-3198-40ca-b458-49f973db8752
status: test
description: Detects rundll32 execution without parameters as observed when running Metasploit windows/smb/psexec exploit module
references:
    - https://bczyz1.github.io/2021/01/30/psexec.html
author: Bartlomiej Czyz, Relativity
date: 2021-01-31
modified: 2023-02-28
tags:
    - attack.lateral-movement
    - attack.t1021.002
    - attack.t1570
    - attack.execution
    - attack.t1569.002
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        CommandLine:
            - 'rundll32.exe'
            - 'rundll32'
    condition: selection
falsepositives:
    - False positives may occur if a user called rundll32 from CLI with no options
level: high

KQL (Azure Sentinel)

imProcessCreate
| where TargetProcessCommandLine in~ ("rundll32.exe", "rundll32")

Required Data Sources

False Positive Guidance

• False positives may occur if a user called rundll32 from CLI with no options

MITRE ATT&CK Context

• Tactic: Lateral Movement
• Tactic: Execution
• Technique: T1021.002 — T1021.002
• Technique: T1570 — T1570
• Technique: T1569.002 — T1569.002

References

• https://bczyz1.github.io/2021/01/30/psexec.html
• SigmaHQ Rule