If you have Dropbox installed, take a look at
System Preferences > Security & Privacy > Accessibility tab. Notice something? Ever wondered how it got in there? Do you think you might have put that in there yourself after Dropbox asked you for permission to control the computer?
No, I can assure you that your memory isn’t faulty. You don’t remember doing that because Dropbox never presented this dialog to you, as it should have[…]
Indeed, even with your admin password, it still shouldn’t be able to get into Accessibility. Clearly Dropbox’s coders have been doing some OS X hacking on company time.
I really have nothing to say other than give Dropbox a huge facepalm over this entire thing. Modifying sensitive areas without permission? Seriously Dropbox? I expected better of you. ↩