I was hacked, how can I stop it.

[theinsaneabyss]

The other evening i was watching a movie through my apple TV when suddenly it turned off. I promptly turned it back on again and didn't think anything of it.
Then a little later it turned off again, only this time it didn't just turn off but the display switched to my desk top.
As I sat there I could see the curser move about the screen as, whoever it was, tried to bring down the menu to turn off the mirroring.
Strange thing though. I looked at my Mac and there was no movement on the Mac desk top. Only on the mirrored desktop.
I have increased the security, changed passwords, done everything I possibly can on the Mac to try and stop it happening again but, and this is the problem I am facing. How will I know if they do it again, as there was no evidence of it from the actual Mac only from the mirrored desktop.

Any suggestions?

 

[vansmith]

Changing your wireless password was a good start. What sort of encryption are you using? WPA2 or WEP? If the latter, you really should switch to WPA2.

In System Preferences > Sharing, do you have screen sharing enabled? If not, do you have any other remote access software installed?

Finally, login to your router's configuration page and take a look at the list of connected clients (I can provide more details but I'd need to know the make and model of your router) and see if some unknown device is connected.

 

[theinsaneabyss]

HI Vansmith

Thanks for the swift response. The router is set to WPA Auto (should I change?)
As for sharing, I only have whats needed for the Apple TV and have no other remote access software installed.

Oddly enough while I am sat here and the screen sharing icon keeps popping up every now and then at the top of the screen. As soon as I click on it and bring down the menu it quickly disappears. Don't know if this is connected or just a glitch with Yosemite. (installed an hour or so after the hack)