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

Results forsys.copack.cn

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2018-07-12T05:27:25.886	2018-07-12T00:00:00	2019-09-14T12:00:00	sys.copack.cn	sys.copack.cn	C=US, O=DigiCert Inc, OU=www.digicert.com, CN=Secure Site Extended Validation CA
2017-09-11T18:02:40.141	2017-08-15T00:00:00	2019-09-14T23:59:59	sys.copack.cn	sys.copack.cn	C=US, O=Symantec Corporation, OU=Symantec Trust Network, CN=Symantec Class 3 EV SSL CA - G3
2017-08-15T00:45:01.858	2017-08-15T00:00:00	2019-09-14T23:59:59	sys.copack.cn	sys.copack.cn	C=US, O=Symantec Corporation, OU=Symantec Trust Network, CN=Symantec Class 3 EV SSL CA - G3
2015-07-09T14:20:25.568	2015-07-03T00:00:00	2017-08-01T23:59:59	sys.copack.cn	sys.copack.cn	C=US, O=Symantec Corporation, OU=Symantec Trust Network, CN=Symantec Class 3 EV SSL CA - G3
2015-07-03T02:45:01.442	2015-07-03T00:00:00	2017-08-01T23:59:59	sys.copack.cn	sys.copack.cn	C=US, O=Symantec Corporation, OU=Symantec Trust Network, CN=Symantec Class 3 EV SSL CA - G3
2014-12-18T02:50:13.819	2013-07-05T00:00:00	2015-07-05T23:59:59	sys.copack.cn	sys.copack.cn	C=US, O="VeriSign, Inc.", OU=VeriSign Trust Network, OU=Terms of use at https://www.verisign.com/rpa (c)06, CN=VeriSign Class 3 Extended Validation SSL CA