Hacked
how to find out if my computer was hacked?
i think some one has hacked my computer because someone else have password to my skype ID that i use on this computer only.
Change your User login password.
Reset the user password in OS X Lion, Mountain Lion and Mavericks
https://discussions.apple.com/docs/DOC-4101
Login to Skype and change your password.
https://login.skype.com/login?message=signin_continue
If you have used the password on any other account, change you password on each account. I suggest you get a password keeper like 1Password my favorite or check out LastPass.