Does ransomware on Bootcamp Windows affects macOS disk?
Because windows can't write to a Mac formatted disk, it can't do anything bad to it. If the ransomware contained an HFS+ or APFS driver for windows, it could in theory also attack the host Mac drive. Of course that won't be a problem, because your Mac drive is all backed up safe and secure with Time Machine. But back to ransomware, does Windows ransomware typically attack/encrypt your external drives too, or just the main boot drive containing the current system?