PUA - Chisel Tunneling Tool Execution — Sigma Rule

Rule metadata and linked tags

Author: Florian Roth (Nextron Systems). Source status: test; severity: high. Source dates: 2022-09-13 / 2023-02-13.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: ed3ead46ee0731b89a9fe6d95d2a5d4ba9e8050d460fb3bb1e09b97b69cb2f6d

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: PUA - Chisel Tunneling Tool Execution
id: 8b0e12da-d3c3-49db-bb4f-256703f380e5
related:
    - id: cf93e05e-d798-4d9e-b522-b0248dc61eaf
      type: similar
status: test
description: Detects usage of the Chisel tunneling tool via the commandline arguments
references:
    - https://github.com/jpillora/chisel/
    - https://arcticwolf.com/resources/blog/lorenz-ransomware-chiseling-in/
    - https://blog.sekoia.io/lucky-mouse-incident-response-to-detection-engineering/
author: Florian Roth (Nextron Systems)
date: 2022-09-13
modified: 2023-02-13
tags:
    - attack.command-and-control
    - attack.t1090.001
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        Image|endswith: '\chisel.exe'
    selection_param1:
        CommandLine|contains:
            - 'exe client '
            - 'exe server '
    selection_param2:
        CommandLine|contains:
            - '-socks5'
            - '-reverse'
            - ' r:'
            - ':127.0.0.1:'
            - '-tls-skip-verify '
            - ':socks'
    condition: selection_img or all of selection_param*
falsepositives:
    - Some false positives may occur with other tools with similar commandlines
level: high

Original YAML and metadata in JSON

False positives

• Some false positives may occur with other tools with similar commandlines

Source references

• https://github.com/jpillora/chisel/
• https://arcticwolf.com/resources/blog/lorenz-ransomware-chiseling-in/
• https://blog.sekoia.io/lucky-mouse-incident-response-to-detection-engineering/