"The I put all the information I don't want to lose in dropbox." I don't think its healthy to consider cloud storage backup. For example I am pretty sure you could loose everything to Ransomware.
I know Dropbox sells Extended Version History [1] as an add-on, but it'll be awfully nice if Pro users had maybe 60 days of file history, versus 30 days for free. Just a thought.
https://www.dropbox.com/en/help/11
So, as long as you notice before the clock runs out, you should be able to recover from ransomware via file history.
[I work for Dropbox, but am not speaking on behalf of my employer.]