Permission for Authenticated Users - Ransomware?

I read an article that suggested that changing your permissions on your backup drive(s) to not allow "Modify" would prevent ransomware from encrypting the drive. It sounds sensible but does anyone know if it is a good path to go down? I am running Malwarebytes Beta Anti-Ransomeware software but was just looking for that extra protection.

Many of my files are also on Dropbox and as I understand that, if there is a ransomeware attack, Dropbox backs up a copy of any file changed before the new (encrypted file) is written. It does this backup for any file and keeps the backups for a minimum of 30 days. So I can get them back. Just looking for any extra protection.

If there is a thread on this subject, please point me to it as I couldn't find one.

Thank You.

You'd be better off unplugging the drive.

If you change the file permissions of course any malware could (if running with administrator privileges) change them back anyway before running the encryption.

The dropbox facility you mention is certainly useful too.

Thanks for the great idea. My 2 backups are NAS boxes that can be scheduled to spin down except when I schedule a backup. That will work and will solve a problem I had concerning one of my backup utilities that needs the modify on.