Ransomware detection

How good is Avast at detecting Ransomware, if at all?

avas detects several versions of it as you can see in the vps history
https://www.avast.com/virus-update-history

Currently avast is working on a prevention module.
When it will be released/added to the avast software is not yet known.

We were hit by CryptoWall at the beginning of February, and a number of files were damaged beyond repair. Although it was a User Workstation that was infected, it began corrupting all of the files he had permissions to on the Network Shares. It is very difficult to spot this in-progress, as there were no signs of anything wrong at the Workstation itself (and it was quite a few days before we found all of the damaged files). Fortunately, we had backups available, and nothing was lost.

It is very important that users do not have permissions for network resources that they do not need. In this way, you can limit the damage caused.

It also proofs the need to have/keep recent backups.

I must say that the files affected were on a server that uses differential backups, and a spike in the size of the differential backup gave a good indication that a large number of files had been altered. This sort of thing is much less obvious when using full backups, as the total size would not have altered all that much.