[jpalomaki]

Given the amount of vulnerabilities in commonly used applications, they would not need the auto update to infect your computer with malware. Just modify some existing document stored in your computer and wait for you to open it.

And to do that, there's no need to work with Dropbox. Eve could just work her way through your colleagues you are sharing files with to find the weakest link, plant the documents on his computer and wait for them to automatically sync to yours.