many ways to avoid this
1) uninstall all Adobe products, as you should have long ago...
2) Back up your data regularly, and not just by copying to an external HDD (where the same virus can easily find the same files and encrypt them there too) Use a real backup application that actually creates backup files, or an online backup service like Carbonite or BackBlaze (and not the one in Windows Vista or 7, it's bugged, and has been since it's inception).
3) Don't use IE, and use noScript or similar blocking technology to prevent anything more than simple HTML code from displaying.
4) Actually use an AV product with adware/spyware tools. I'd stay away from Symantec of McAfee retail products (though McAfee ePO is not bad), but many other products are highly rated.
5) never click on a link in an e-mail unless you know who and WHY they're sending you a link (aka you were expecting it).
6) don't store personal information that can be used against you on your PC at all unless those files are encrypted (and only do so if you HAVE to.)