I found, by accident, a very useful tip to make the FTP service within the MBL a lot more reliant against FTP hack attempts.
Gain access to the Lunux command shell and open within the
nano text editor `/etc/vsftpd.conf’.
Add ONLY the following line to the configuration file:
Restart the FTP service using:
What this does is when a unknown user-name is put in or the right user-name but wrong password then the connected session is forced to wait 30 seconds before being told the login was unsuccessful.
Hope that tip of use.