Potential Command Line Path Traversal Evasion Attempt — Sigma Rule

Rule metadata and linked tags

Author: Christian Burkard (Nextron Systems). Source status: test; severity: medium. Source dates: 2021-10-26 / 2023-03-29.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 9c8ebfdde8b3438dd1e828c090ee3e70c47f7082cdcb09141bf978dbcb09d12c

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 Command Line Path Traversal Evasion Attempt
id: 1327381e-6ab0-4f38-b583-4c1b8346a56b
status: test
description: Detects potential evasion or obfuscation attempts using bogus path traversal via the commandline
references:
    - https://twitter.com/hexacorn/status/1448037865435320323
    - https://twitter.com/Gal_B1t/status/1062971006078345217
author: Christian Burkard (Nextron Systems)
date: 2021-10-26
modified: 2023-03-29
tags:
    - attack.stealth
    - attack.t1036
logsource:
    category: process_creation
    product: windows
detection:
    selection_1:
        Image|contains: '\Windows\'
        CommandLine|contains:
            - '\..\Windows\'
            - '\..\System32\'
            - '\..\..\'
    selection_2:
        CommandLine|contains: '.exe\..\'
    filter_optional_google_drive:
        CommandLine|contains: '\Google\Drive\googledrivesync.exe\..\'
    filter_optional_citrix:
        CommandLine|contains: '\Citrix\Virtual Smart Card\Citrix.Authentication.VirtualSmartcard.Launcher.exe\..\'
    condition: 1 of selection_* and not 1 of filter_optional_*
falsepositives:
    - Google Drive
    - Citrix
level: medium

Original YAML and metadata in JSON

False positives

• Google Drive
• Citrix

Source references

• https://twitter.com/hexacorn/status/1448037865435320323
• https://twitter.com/Gal_B1t/status/1062971006078345217