The Windows Club has published a pretty extensive list of tools to help you if you get zapped. First of all, it’ll probably be Petya or Locky as they’re the most common ones encountered currently. First you have to identify the malware. You upload the ransom note or a file which has been encrypted by the malware (and hope it identifies the malware) here: https://id-ransomware.malwarehunterteam.com/index.php
There’s a great list of the tools here: http://www.thewindowsclub.com/list-ransomware-decryptor-tools and each tool is specific to the malware identified, so…step one is very important.
There are also several intrusion detection tools, but according to the Windows Club, WinPatrol is free and probably the best. You can read about it at the linked url.
There are also free anti-Ransomware tools. I've written about one, but there are several, and you can read about (and get links to them) here: http://www.thewindowsclub.com/free-anti-ransomware-tools
Probably another article to read to help you get organized about what you should do if you get attacked is located here: http://www.thewindowsclub.com/what-to-do-after-ransomware-attack
The most important thing to is have recent backups, so don't be lazy: Make one now. The only backup you'll ever regret making is the one you didn't make.
Hope this helps in case you get hit. I’ve bookmarked the links above…and you might consider doing the same.
Have a great weekend!
Sources:
http://www.thewindowsclub.com/list-ransomware-decryptor-tools
https://www.winpatrol.com/
http://www.thewindowsclub.com/free-anti-ransomware-tools