PUA - RunXCmd Execution

Hunt Hypothesis

Detects the use of the RunXCmd tool to execute commands with System or TrustedInstaller accounts

Detection Rule

Sigma (Original)

title: PUA - RunXCmd Execution
id: 93199800-b52a-4dec-b762-75212c196542
status: test
description: Detects the use of the RunXCmd tool to execute commands with System or TrustedInstaller accounts
references:
    - https://www.d7xtech.com/free-software/runx/
    - https://www.winhelponline.com/blog/run-program-as-system-localsystem-account-windows/
author: Florian Roth (Nextron Systems)
date: 2022-01-24
modified: 2023-02-14
tags:
    - attack.execution
    - attack.t1569.002
    - attack.s0029
logsource:
    category: process_creation
    product: windows
detection:
    selection_account:
        CommandLine|contains:
            - ' /account=system '
            - ' /account=ti '
    selection_exec:
        CommandLine|contains: '/exec='
    condition: all of selection_*
falsepositives:
    - Legitimate use by administrators
level: high

KQL (Azure Sentinel)

imProcessCreate
| where (TargetProcessCommandLine contains " /account=system " or TargetProcessCommandLine contains " /account=ti ") and TargetProcessCommandLine contains "/exec="

Required Data Sources

False Positive Guidance

• Legitimate use by administrators

MITRE ATT&CK Context

• Tactic: Execution
• Technique: T1569.002 — T1569.002

References

• https://www.d7xtech.com/free-software/runx/
• https://www.winhelponline.com/blog/run-program-as-system-localsystem-account-windows/
• SigmaHQ Rule