SubSpy 🔍

SubSpy is a Chrome/Firefox extension that discovers subdomains of the website you are currently visiting. It uses a customizable wordlist and DNS over HTTPS (DoH) to scan efficiently.

Features

• 🚀 One-click scan of the active tab's domain
• 📂 Use built-in or upload your own wordlist
• ⏸️ Pause / ▶️ Resume / ⏹️ Stop scans
• 📊 Real-time progress & found subdomain count
• 📥 Export results as .txt
• 🖱️ Click to copy subdomains

Installation

Chrome

git clone https://github.com/ghaziwali/SubSpy.git

1. Open Chrome → Extensions → Load unpacked
2. Select the SubSpy folder

Firefox

1. Rename manifest-firefox.json to manifest.json in the SubSpy folder
2. Add this polyfill at the top of popup.js so Firefox recognizes Chrome APIs:

// Polyfill so browser.* works in Firefox
if (typeof browser === "undefined") {
  var browser = chrome;
}

3. Open Firefox → about:debugging → This Firefox → Load Temporary Add-on
4. Select the Firefox manifest

⚠️ Note: Firefox does not fully support MV3 service workers. All scanning logic runs from the popup.

Usage

1. Navigate to a website you want to scan
2. Click the SubSpy icon in your browser toolbar
3. Click Scan to start scanning subdomains
4. Pause, resume, or stop scans as needed
5. Export found subdomains using the Download button
6. Click individual subdomains to copy them to your clipboard

Contributing

Contributions are welcome!

Please open an issue or submit a pull request if you want to add features, fix bugs, or improve documentation.