Why can a website scan my internal network and how can I stop it?

Some malicious download sites run invisible scripts that silently scan the ports of your `localhost` (127.0.0.1) or your home network (192.168.x.x) looking for vulnerabilities in your local area network.

Perimeter shielding for local IPs and localhost

In-browser port scanning is carried out via local AJAX requests. AdBlock Network blocks these calls at the root. The extension performs read-only asynchronous requests to multiple independent endpoints to keep your firewall up to date, blocking any outgoing web requests targeting your local address at the Address layer.