Unfortunately, brute force attacks can get around any password. And in most instances, if you have been hit once they will return. There is a Panasonic approved product, Control Phreak from Callista.net that has stopped hacking attacks on Panasonic systems while allowing full use of the PBX and voicemail. Price is $495 including remote installation and 24 hour support. Further information on PBX hacking is available on this website.