PUA - Chisel Tunneling Tool Execution

Hunt Hypothesis

Detects usage of the Chisel tunneling tool via the commandline arguments

Detection Rule

Sigma (Original)

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

KQL (Azure Sentinel)

imProcessCreate
| where TargetProcessName endswith "\\chisel.exe" or ((TargetProcessCommandLine contains "exe client " or TargetProcessCommandLine contains "exe server ") and (TargetProcessCommandLine contains "-socks5" or TargetProcessCommandLine contains "-reverse" or TargetProcessCommandLine contains " r:" or TargetProcessCommandLine contains ":127.0.0.1:" or TargetProcessCommandLine contains "-tls-skip-verify " or TargetProcessCommandLine contains ":socks"))

Required Data Sources

False Positive Guidance

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

MITRE ATT&CK Context

• Tactic: Command and Control
• Technique: T1090.001 — T1090.001

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/
• SigmaHQ Rule