The number of nasty things that can happen to systems with old versions of Flash is growing. See this article for an overview. Although Windows systems are the big targets, there is nothing stopping the technique described being used against Mac and Linux laptop and desktop systems.
We try to make 3rd-party software updates available to our Windows users, but the system is far from perfect. The saving grace is that CBC Windows users are pretty good about not saving files on local drives. So ransomware is not quite as dangerous. However, for personal systems, or for systems not in the Chemistry domain, I strongly recommend that you check your version of Flash by going to here. You should run the check found there from any of the browsers you use.
I just ran the check myself on one of my systems, and I see that the Adobe site is not completely clear about whether the version I was using was out-of-date on not. (It was out-of-date.) You can reference this page to see what the current version is for your OS and browser.