Apex domains cannot have CNAME records.
Question and response
Question
dig corisvc.info. NS
Answer
corisvc.info. 5 NS ns63.domaincontrol.com.
corisvc.info. 5 NS ns64.domaincontrol.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0