VsCode Code Tunnel Execution File Indicator

Status: test
Severity: medium
Log source: category file_event, product windows
Author: Nasreddine Bencherchali (Nextron Systems)
Source: github.com/SigmaHQ/sigma

Detects the creation of a file with the name "code_tunnel.json" which indicate execution and usage of VsCode tunneling utility. Attackers can abuse this functionality to establish a C2 channel

Known false positives

Legitimate usage of VsCode tunneling functionality will also trigger this

MITRE ATT&CK coverage

Tactic	Techniques
Command & Control	No specific technique

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 11: FileCreate

Rule body

title: VsCode Code Tunnel Execution File Indicator
id: 9661ec9d-4439-4a7a-abed-d9be4ca43b6d
status: test
description: |
    Detects the creation of a file with the name "code_tunnel.json" which indicate execution and usage of VsCode tunneling utility. Attackers can abuse this functionality to establish a C2 channel
references:
    - https://ipfyx.fr/post/visual-studio-code-tunnel/
    - https://badoption.eu/blog/2023/01/31/code_c2.html
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-10-25
tags:
    - attack.command-and-control
    - detection.threat-hunting
logsource:
    category: file_event
    product: windows
detection:
    selection:
        TargetFilename|endswith: '\code_tunnel.json'
    condition: selection
falsepositives:
    - Legitimate usage of VsCode tunneling functionality will also trigger this
level: medium

Stages and Predicates

Stage 0: `condition`

selection

Stage 1: `selection`

selection:
    TargetFilename|endswith: '\code_tunnel.json'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`TargetFilename`	ends_with	`\code_tunnel.json` corpus 2 (sigma 2)	`field:"TargetFilename" kind:ends_with value:"\code_tunnel.json"`