I've noticed based on the logging of my NAS that me IP is targetted by a hacker. I already took action by automaticly ban the IP address permantly after 5 unsuccesfull login attemps. Unfortunatly the hack is being processed by using multple different ip adresses so to me this security attempt is not valid as it only works till the hacker runs out of ip adresses or when he gets the right username/password combination. Which sounds rather tricky to me and I don`t want to wait till 1 of these 2 events will happen.

I googled some of the IP adresses which are banned and they show up on several 'hacker' sites as hacker ip`s. Should I do something and are my worries justified?