Detect IDE Tunneling in Elastic Security
Adversaries may abuse Integrated Development Environment (IDE) software with remote development features to establish an interactive command and control channel on target systems within a network. IDE tunneling combines SSH, port forwarding, file sharing, and debugging into a single secure connection, letting developers work on remote systems as if they were local. Unlike SSH and port forwarding, IDE tunneling encapsulates an entire session and may use proprietary tunneling protocols alongside SSH, allowing adversaries to blend in with legitimate development workflows. Some IDEs, like Visual Studio Code, provide CLI tools (e.g., code tunnel) that adversaries may use to programmatically establish tunnels and generate web-accessible URLs for remote access. These tunnels can be authenticated through accounts such as GitHub, enabling the adversary to control the compromised system via a legitimate developer portal.
MITRE ATT&CK
- Tactic
- Command and Control
- Technique
- T1219 Remote Access Tools
- Sub-technique
- T1219.001 IDE Tunneling
- Canonical reference
- https://attack.mitre.org/techniques/T1219/001/
Elastic Detection Query
process where event.type == "start"
and (
process.name in~ (
"code.exe", "code-tunnel.exe", "code-insiders.exe", "code", "code-tunnel",
"devtunnel.exe", "devtunnel", "jetbrains-gateway.exe", "gateway.exe",
"remote-dev-server.sh", "idea.sh", "pycharm.sh",
"cursor.exe", "cursor", "windsurf.exe"
)
or process.command_line like~ (
"*tunnel*", "*serve-web*", "*--remote-tunnel*",
"*dev-tunnel*", "*--host 0.0.0.0*",
"*--accept-server-license-terms*", "*--no-browser*"
)
)Detects IDE tunneling activity (T1219.001) via Elastic EQL by matching process creation events against known IDE tunnel binary names (VS Code, devtunnel, JetBrains Gateway, Cursor, Windsurf) and command-line arguments indicative of remote tunnel establishment. Uses case-insensitive matching across Windows and Linux process telemetry.
Data Sources
Required Tables
False Positives & Tuning
- Authorized software developers using VS Code Remote Tunnels or JetBrains Gateway for legitimate remote development on approved cloud VMs or home office machines.
- DevOps engineers using the devtunnel CLI as part of Azure Developer CLI (azd) workflows to expose local services for integration testing in CI/CD pipelines.
- IT support staff or platform engineering teams using Cursor or Windsurf AI editors with built-in remote SSH capabilities for sanctioned pair programming or incident response on remote hosts.
Other platforms for T1219.001
Testing Methodology
Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1VS Code CLI Tunnel Initiation
Expected signal: Sysmon Event ID 1: Process Create with Image=code.exe, CommandLine containing 'tunnel --accept-server-license-terms --name test-tunnel'. Sysmon Event ID 22: DNS query for tunnels.api.visualstudio.com. If tunnel starts: Sysmon Event ID 3 for HTTPS connection to tunnel relay servers.
- Test 2DevTunnel CLI Tunnel Creation
Expected signal: Sysmon Event ID 1: Process Create with Image=devtunnel.exe, CommandLine containing 'host --port 8080 --allow-anonymous'. Sysmon Event ID 22: DNS query for devtunnels.ms. Sysmon Event ID 3: Network connection to Microsoft tunnel infrastructure.
- Test 3VS Code Tunnel Persistence via Scheduled Task
Expected signal: Security Event ID 4698: Scheduled task created with TaskContent containing 'code.exe tunnel'. Sysmon Event ID 1: Process Create for schtasks.exe with command line showing the tunnel command. The scheduled task itself won't execute (non-existent path) but the creation event fires.
References (8)
- https://attack.mitre.org/techniques/T1219/001/
- https://www.sentinelone.com/labs/operation-digital-eye-chinese-apt-compromises-critical-digital-infrastructure-via-visual-studio-code-tunnels/
- https://unit42.paloaltonetworks.com/stately-taurus-abuses-vscode-southeast-asian-espionage/
- https://medium.com/@truvis.thornton/visual-studio-code-embedded-reverse-shell-and-how-to-block-create-sentinel-detection-and-add-e864ebafaf6d
- https://learn.microsoft.com/en-us/azure/developer/dev-tunnels/overview
- https://code.visualstudio.com/docs/remote/tunnels
- https://learn.microsoft.com/en-us/defender-endpoint/advanced-hunting-deviceprocessevents-table
- https://github.com/SigmaHQ/sigma/tree/master/rules/windows/process_creation
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