How does Onedrive stop ransomware if it syncs everything?

[spotrot]

I understand how manually uploading your files to Onedrive helps resist ransomware.
Your computer is infected, Onedrive isn't.

But... if you use the automatic desktop mirror/sync on Windows 10 and 11... doesn't that just copy the encrypted files? Am I not understanding how the sync works?

Say I get infected.
My files are now being encrypted, then deleted.
Doesn't Onedrive just sync this, leaving you with encrypted files?

Summary: How does Onedrive auto-syncing on Windows 11 desktop folders protect against ransomware if it just mirrors deletions/encryption?

 

[interlocutor1980]

if there is a ransomware encrypted file on OneDrive, that must have been encrypted before it was uploaded to OneDrive

The infection is not actually on OneDrive, the process that encrypted your files was on your PC, so downloading or syncing one of those encrypted files or any other file from OneDrive, will not affect your PC, If you reset, reinstall windows or clean your pc from any infection or ransomware.

 

[spotrot]

That's how manually syncing files works. I said that.
You are the one moving the files. Without you, the files do not move.

My question was how Onedrive automatically uploading/downloading or "syncing" handles this. Wouldn't this automatically sync all the unwanted changes from a virus, completely bypassing the point of backups?