It can be anything! An apex, subdomain, or even a URL.
Results forvo.msecnd.net.office.eucouncilo365proxy.eucouncileupoc.myshn.eu
www.vo.msecnd.net.office.eucouncilo365proxy.eucouncileupoc.myshn.eumsecnd.net.office.eucouncilo365proxy.eucouncileupoc.myshn.eunet.office.eucouncilo365proxy.eucouncileupoc.myshn.euoffice.eucouncilo365proxy.eucouncileupoc.myshn.eueucouncilo365proxy.eucouncileupoc.myshn.eueucouncileupoc.myshn.eumyshn.eueu