Detection rules › Sigma

PUA - Chisel Tunneling Tool Execution

Status
test
Severity
high
Log source
product windows, category process_creation
Author
Florian Roth (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects usage of the Chisel tunneling tool via the commandline arguments

MITRE ATT&CK coverage

TacticTechniques
Command & ControlT1090.001 Proxy: Internal Proxy

Event coverage

Rule body yaml

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

Stages and Predicates

Stage 0: condition

selection_img or all of selection_param*

Stage 1: selection_img

selection_img:
    Image|endswith: '\chisel.exe'

Stage 2: selection_param1

selection_param1:
    CommandLine|contains:
        - 'exe client '
        - 'exe server '

Stage 3: selection_param2

selection_param2:
    CommandLine|contains:
        - '-socks5'
        - '-reverse'
        - ' r:'
        - ':127.0.0.1:'
        - '-tls-skip-verify '
        - ':socks'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
CommandLinematch
  • r:
  • -reverse
  • -socks5
  • -tls-skip-verify
  • :127.0.0.1:
  • :socks
  • exe client
  • exe server
Imageends_with
  • \chisel.exe