A virus encrypted my hard drive

I have a kaspersky internet security 2017, and I already checked it, but there was no malware or ransomware.

For me, your comment seems so malicious. Can you please upload the photo of that?

Malim

I also find it hard to believe it. If you downloaded Beta 5 using the link on our website https://strategyquant.com/betaversion4 there is NO virus. 

I just downloaded it and checked it with antivirus software just to be sure.

And we would definitely not blackmail you by encrypting your disc.

If you really see this message please make a screenshot or photo with your mobile and attach it here.j

stupidly I did not take pictures, I restarted the pc in panic, anyway I solved it, my son had synchronized all the data on a cloud, and restarted the PC at its initial state, thanks, I think I'll use the old version, for me it remains perfect.

Beta 5 doesn't have any virus, but it could have been infected during download - if you have virus on your computer.

You should be able to use Beta 5, it has many improvements over Beta 4.