ast url detonate

Suspecting a URL is malicious is one thing, but proving it requires a safe way to watch it behave. AST URL Detonate provides a self-hosted sandbox environment for security engineers to safely trigger, observe, and capture URL behavior without risking their primary workstation or local network.

What it does

• Remote Detonation triggers suspicious URLs inside a dedicated headless Chromium instance on a user-controlled Linux host.
• Evidence Capture retrieves the full redirect chain, DOM snapshots, HAR files, pcap network traffic, and screenshots.
• Secure File Retrieval downloads payloads and malware samples from the sandbox to the workstation only with explicit user flags.
• Infrastructure Isolation uses iptables egress allowlisting and dedicated subnets to prevent malware from scanning the local network.
• Verified Bundles generates a cryptographically signed artifact bundle for every detonation run for chain-of-custody.

How it works

1. Dry Run the url-detonate run command to generate a unique execution token for a specific URL.
2. Execute the detonation by replaying the token, which triggers the remote browser on the sandbox host.
3. Poll Status via the CLI or MCP tool to monitor progress and capture completion events.
4. Fetch Artifacts to pull the HAR, screenshots, and logs back to the local environment for analysis.

Frameworks & tools

The client requires Python 3.12+ and connects via SSH to a Linux sandbox host. The server kit runs on Docker with iptables for network isolation. It integrates with Claude Code and Cursor via the included MCP server.

Why this beats prompting it yourself

Generic AI agents often refuse to visit suspicious links or, worse, visit them directly from their own IP, alerting attackers. This skill enforces a strict air-gapped workflow, ensuring all risky network activity happens on an isolated host while providing the agent with the specific CLI and MCP tools to parse security artifacts accurately.

Use cases

• Phishing Analysis to follow shortened or obscured redirect chains to the final destination.
• Malware Triage to capture and download files served by suspicious domains in a controlled environment.
• Threat Hunting to record the network traffic (pcap) generated by a suspicious landing page.
• Evidence Collection for security reports requiring visual proof and DOM content of a live threat.

Known limitations

Requires a dedicated Linux host with Docker and root access for initial server setup. Does not support macOS or Windows for the sandbox host. Does not provide automated reputation verdicts.