avast has been working on something to prevent systems from getting infected with ransomware for many months.
But they are very quiet about it so it is unknown to us users what the status/progress of it is.
Cybercapture can't kick in before a file comes to the system.
Simply because it has to be on the system to create the hash for a file.
If the file is not present, a hash can't be created and therefor not be send to avast.
stopping unauthorized programs from modifying your private files
And how should avast know what files are private or not?
Only way is to tell avast meaning that even if you create e.g. a draft for a letter in notepad that you want to print and send by regular mail to someone, let avast know it is a private file.
Another problem is...
What are unauthorized programs ?
Any file can be changed with e.g. notepad.
So it notepad to be considered as a unauthorized application