A lot of useful infos were collected and shared in this thread! Once more a confirmation of the great value of our community.
Since it wasn't highlighted (or I missed it..) , let me stress a point about backups and ransomware.
Those malwares often sneakily install on your computer and encrypt files for some time prior to reveal themselves. This means that your daily backups, starting at the attack date, are compromised as the living set.
So, to somewhat recover from a ransomware attack, you should have your backups to store a few days of data not just the last one day worth of it.
You also may find useful to read about the
3-2-1 backup strategy and its evolution.