To date I have not (thankfully) had Ransomware on any of my PC's.  I do run Malwarebytes regularly (free version).  Checking their site it says it will find Ransomware before it actives.  I don't know if it does or not. 

I would suggest downloading it and running it on and PC's and Servers to make sure.

We have some VERY strict rules on E-mail (that is how most Ransomware is installed on PC's).  NO ONE is allowed to access their personal e-mail on any of our equipment.  All company email comes to one of 2 email accounts and both of us will not open ANYTHING if we are not expecting an email from that client.  If we think it could be legitimate we will call the individual to assure that they sent it.

Dusty