al2mon

al2mon

al2mon is a lightweight, real-time subdomain monitoring tool powered by Certificate Transparency (CT) logs. It detects new subdomains as soon as SSL certificates are issued and sends instant notifications to Discord.

Features

• 🚀 Real-time Detection: Monitors CT logs for new certificates instantly.
• 🔄 Deduplication: Prevents duplicate alerts for the same subdomain (1-hour cache).
• 🌐 Active DNS Check: Automatically verifies if the subdomain resolves to an IP address before alerting.
• 🔔 Discord Notifications: Sends rich alerts via Webhook.
• 🖥️ Daemon Mode: Runs in the background as a detached process.
• 🎨 Beautiful UI: Clean CLI interface with ASCII banner.

Quick Install (Go 1.21+)

If you have Go installed, you can install al2mon directly:

go install github.com/AltugKale/al2mon@latest

Installation (Source)

git clone https://github.com/AltugKale/al2mon.git
cd al2mon
go build .

Usage

Basic Monitoring

To monitor a single domain:

./al2mon -target example.com

Options

• -target: Target domain to monitor (comma separated). Overrides configuration file targets.
• -daemon: Run in background.
• -discord: Enable Discord notifications (requires webhook_url in config.yaml).

Configuration

The tool looks for a configuration file in the following order:

1. config.yaml in the current directory.
2. ~/.config/al2mon/config.yaml (Created automatically if not found).

Example config.yaml:

targets:
  - example.com
  - test.com
webhook_url: "https://discord.com/api/webhooks/..."

Usage Examples

Monitor specific targets (overrides config):

al2mon -target google.com,yahoo.com

Run with default config and Discord notifications:

al2mon -discord

Run in background:

al2mon -daemon -discord

Contributing

Pull requests are welcome! For major changes, please open an issue first to discuss what you would like to change.

License

MIT