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

Results for*.pinglabs.net

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2016-09-18T04:54:33.554	2012-06-21T10:18:46	2014-06-23T07:50:25	*.pinglabs.net	*.pinglabs.net	C=IL, O=StartCom Ltd., OU=Secure Digital Certificate Signing, CN=StartCom Class 2 Primary Intermediate Server CA
2016-09-18T04:54:33.554	2012-06-21T10:18:46	2014-06-23T07:50:25	*.pinglabs.net	*.pinglabs.net	C=IL, O=StartCom Ltd., OU=Secure Digital Certificate Signing, CN=StartCom Class 2 Primary Intermediate Server CA
2015-02-05T13:19:52.225	2014-07-14T23:00:54	2016-07-15T20:11:50	*.pinglabs.net	*.pinglabs.net	C=IL, O=StartCom Ltd., OU=Secure Digital Certificate Signing, CN=StartCom Class 2 Primary Intermediate Server CA
2015-02-05T13:19:52.225	2014-07-14T23:00:54	2016-07-15T20:11:50	*.pinglabs.net	*.pinglabs.net	C=IL, O=StartCom Ltd., OU=Secure Digital Certificate Signing, CN=StartCom Class 2 Primary Intermediate Server CA