1) Are you sure that they are using the subdomain? They could be connecting via ...

		supermatt 4 months ago \| parent \| context \| favorite \| on: Ask HN: How did the internet discover my subdomain... 1) Are you sure that they are using the subdomain? They could be connecting via IP or an alternate host address. 2) Are you using TLS? Unless you are using a wildcard cert, then the FQDN will have been published as part of the certificate transparency logs.