It can be anything! An apex, subdomain, or even a URL.

Results for*.null404.net

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2021-04-22T14:10:31.328	2021-04-22T00:00:00	2022-04-21T23:59:59	sni.cloudflaressl.com	*.null404.net	C=US, O="Cloudflare, Inc.", CN=Cloudflare Inc ECC CA-3
2021-04-22T14:10:31.328	2021-04-22T00:00:00	2022-04-21T23:59:59	sni.cloudflaressl.com	*.null404.net	C=US, O="Cloudflare, Inc.", CN=Cloudflare Inc ECC CA-3
2020-07-03T04:22:19.208	2020-05-23T00:00:00	2021-05-23T12:00:00	sni.cloudflaressl.com	*.null404.net	C=US, O="Cloudflare, Inc.", CN=Cloudflare Inc ECC CA-3
2020-07-03T04:22:19.208	2020-05-23T00:00:00	2021-05-23T12:00:00	sni.cloudflaressl.com	*.null404.net	C=US, O="Cloudflare, Inc.", CN=Cloudflare Inc ECC CA-3
2020-05-23T21:25:55.86	2020-05-23T00:00:00	2021-05-23T12:00:00	sni.cloudflaressl.com	*.null404.net	C=US, O="Cloudflare, Inc.", CN=Cloudflare Inc ECC CA-3
2020-05-23T21:25:55.86	2020-05-23T00:00:00	2021-05-23T12:00:00	sni.cloudflaressl.com	*.null404.net	C=US, O="Cloudflare, Inc.", CN=Cloudflare Inc ECC CA-3