It can be anything! An apex, subdomain, or even a URL.
Results forwww.c3scs.jp.msn.com.office.proxy-o365-lab-eu.cloudexperte.myshn.eu
c3scs.jp.msn.com.office.proxy-o365-lab-eu.cloudexperte.myshn.eujp.msn.com.office.proxy-o365-lab-eu.cloudexperte.myshn.eumsn.com.office.proxy-o365-lab-eu.cloudexperte.myshn.eucom.office.proxy-o365-lab-eu.cloudexperte.myshn.euoffice.proxy-o365-lab-eu.cloudexperte.myshn.euproxy-o365-lab-eu.cloudexperte.myshn.eucloudexperte.myshn.eumyshn.eueu