How to stop remote connection/intrusion? A person within my network got access to my MacBook Pro through Wi-fi, and somehow now he can connect remotely. I cannot change the Wi-fi password because we both pay for it.  So, my only choice so far is to avoid not to use Wi-Fi at all, until I learn on what to do to remove his fingers of my machine.

I did 3 factory reset, cleaned up all my files but as soon I am within his range he is again messing with my files. I tripled check all my security settings such as firewall, disabled infrared receiver, created a vault, even I now use a firmware password to log into my machine. 

How to stop his remote connection?
Disable (uncheck) in System Preferences+Sharing: 
File Sharing, 
Screen Sharing, 
Remote Management, 
Remote Login + (check in allow access for ?) who has the permission.

also check if there is a user profile set up that is not yours.