Hi @Mark_H,
Unsynced files should always be safe from this type of malware, since changing placeholder files doesn’t have any effect on the cloud data. If the ransomeware is somehow sufficiently intelligent enough to know how to sync files down before messing with then, then it will definitely be harder to combat. If this is a large concern of yours I would recommend using cloud storage that has versioning (you are correct, Amazon Drive does not).
You mentioned “backups”. The current version of odrive is not a “traditional” backup solution, since it is a full-blown sync engine with always-on, bidirectional sync. If traditional backup is your primary use case then we recommend waiting for our forthcoming backup feature.
If you are interested in stopping and starting odrive at certain intervals/times, you can take a look at this thread:
We are thinking about adding a “lock” ability in a future version of odrive, which will prevent interaction with odrive files unless they have been “unlocked” by the user. This could also be used to combat the risk of ransomeware, even if it was intelligent enough to navigate odrive-specific behavior.