I have a Windows 7 Professional 64 bit running as a dedicate server. No one is using the server, no email, no browser downloads, and it's running a recent purchased Avast Internet Security
This weekend, with the office closed, this server got the Black Mamba Ransomware.
So I have to announce that Avast does not stop ransomware, and that I will be looking for alternative protection after clearing up this ransomware.