What can the internet see? Scan yourself

Most break-ins start with something exposed that nobody remembered. Scan your own addresses before someone else does.

19 February 2026 · 1 min read

Attackers don’t start with your website. They scan every address you own and look for anything listening: an old remote desktop, a database, a printer’s web page, a test server from last year.

You can see the same thing they see, for free.

List your public IP addresses and domains. Your ISP, cloud console and DNS records will give you most of them.
Look them up on Shodan or Censys, or run nmap from outside your network.
For each open port, answer: what is it, who owns it, does it need to be public?
Close what isn’t needed. Put admin interfaces behind a VPN or an access proxy.
Repeat monthly, or set up alerts for new open ports.

The first scan is always surprising. Usually the surprise is something someone set up “just for a week”.