Potential Arbitrary File Download Via Cmdl32.EXE — Sigma Rule

Rule metadata and linked tags

Author: frack113. Source status: test; severity: medium. Source dates: 2021-11-03 / 2024-04-22.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 3c415b8adf430ea237f4c30604ff6ce249c439afd833ad271cfadbd9e244c436

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: Potential Arbitrary File Download Via Cmdl32.EXE
id: f37aba28-a9e6-4045-882c-d5004043b337
status: test
description: |
    Detects execution of Cmdl32 with the "/vpn" and "/lan" flags.
    Attackers can abuse this utility in order to download arbitrary files via a configuration file.
    Inspect the location and the content of the file passed as an argument in order to determine if it is suspicious.
references:
    - https://lolbas-project.github.io/lolbas/Binaries/Cmdl32/
    - https://twitter.com/SwiftOnSecurity/status/1455897435063074824
    - https://github.com/LOLBAS-Project/LOLBAS/pull/151
author: frack113
date: 2021-11-03
modified: 2024-04-22
tags:
    - attack.execution
    - attack.stealth
    - attack.t1218
    - attack.t1202
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\cmdl32.exe'
        - OriginalFileName: CMDL32.EXE
    selection_cli:
        CommandLine|contains|all:
            - '/vpn'
            - '/lan'
    condition: all of selection_*
falsepositives:
    - Unknown
level: medium

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://lolbas-project.github.io/lolbas/Binaries/Cmdl32/
• https://twitter.com/SwiftOnSecurity/status/1455897435063074824
• https://github.com/LOLBAS-Project/LOLBAS/pull/151