Welcome to the Dropbox Community, let me send over some tips below regarding your inquiry and we’ll take it from there!
SKBJ ‘s reply could point you towards the right direction, though you may need to dig deeper, depending on the behavior you’ve noticed.
Firstly, as Dropbox syncs any files added to it, a virus or malicious software would get updated to all computers linked to the account accordingly. If the virus or malicious software is in a shared folder, shared folder members and computers may also be affected. That being said, I’d strongly recommend removing it as soon as possible, as it’ll definitely create more issues in the long run.
Secondly, it recently came to attention that connecting or pointing external locations (i.e. Symlinking them) to your Dropbox folder might cause unexpected behavior, so it may appear to you as if files are randomly deleted. That being said, I’d advise you to have a look intro this as well, just as a possible scenario.
Regardless of the cause, if you need further clarifications or you’d like your account reverted back to a particular point in time, my advice would be to reach out directly to our team, who’ll guide you through the necessary steps and actions you’d need to take, so as to revert back to normal operations.
If you decide to go per my advice above, you may keep in mind that I’m always here to pursue a resolution, so please let me know a ticket ID I could reference in your next reply.
I’m looking forward to hearing back from you on this discussion!