What it reads
Public certificate logs, for hostnames that look forgotten or unexpected.
Check 33 of 54 · Domain and registration
Hidden hostnames, explained.
Forgotten test and old systems revealed by public certificate logs.
Engine 1.57.0, read 25 October 2026
Customer scanAdviceReliability: Moderate
Could you lose the domain, or part of it?
What the check does, and where it stops.
Why it matters
Every certificate ever issued for you is on public record. Attackers read that list to find the systems you forgot.
What a finding looks like
What it finds is shown with a recommendation. It is advice, so it never lowers your score. If the check cannot finish, it is recorded as unknown: it carries no penalty, and it is never a pass.
Where its limits are
The hostnames are real. "Looks forgotten" is a judgement, so treat it as a prompt to look.
ReliabilityModerate: confirm before acting
It starts from public certificate logs, a shared source with a strict limit, so it runs on a customer's own verified domains, not on the free check.
Check 33 is one of 10 in Domain and registration. See it in its row on the scanner page, beside the rest of Domain and registration.
See how your domain does.
This check runs on a customer's own verified domains. The free check runs over 40 checks in about 30 seconds, with no account.