It can be anything! An apex, subdomain, or even a URL.
Results forwww.protectioncenter.ext.azure.com.office.proxy-o365-lab-eu.cloudexperte.myshn.eu
protectioncenter.ext.azure.com.office.proxy-o365-lab-eu.cloudexperte.myshn.euext.azure.com.office.proxy-o365-lab-eu.cloudexperte.myshn.euazure.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