$ ping -c1 -p 001d78b8c1a8a6cc27aff77d6140e700 unhack.ca
 
$ curl http://unhack.ca/p/1d78b8c1a8a6cc27aff77d6140e7
 
$ dig 1d78b8c1a8a6cc27aff77d6140e7 @unhack.ca
 
$ dig 1d78b8c1a8a6cc27aff77d6140e7.ns.unhack.ca
 
C:\> nslookup 1d78b8c1a8a6cc27aff77d6140e7 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/1d78b8c1a8a6cc27aff77d6140e7">]>
    <foo>&xxe;</foo>
Waiting for ping...