[Secure for root server]

Hello guys.

Can anyone tell me how to secure my database, my database backdoors, my game backdoors and my homepage backdoors?

I have a root private server, and someone always find my user details and connect to database and delete all server accounts or characters.

Please help me.
Thanks.

Send mee privatmesage and i will help you
GR: Stile mou minima edw na se boithiso