Subdomain takeover: how a dangling CNAME lets someone else serve content on your domain, how to find them safely, and how to prevent the next.
How to Check Open Ports on Your Own Servers (and What to Close)
How to check open ports on infrastructure you own: the commands that work, what each exposed service means, and the decision rule for what to close.
How to Find Subdomains: A Practical Guide to Mapping Your Own Attack Surface
How to find subdomains of a domain you own: certificate transparency, passive DNS, brute force and resolution — plus what to do with the list you get.
Free Security Checks: 6 Things to Test on Your Own Domain
Free security checks: six tests you can run on your own domain today — subdomains, headers, DMARC, open ports, dangling DNS and TLS, with real commands.