can ransomware encrypt Google Drive files using OAuth credentials?

I have created a script (which acts as a backup system for a directory) which uses Google Drive’s OAuth (offline authentication) Credentials to upload files of a directory to google drive, automatically when any content is added to that folder. But it doesn’t sync it (no data mirroring), to protect the backed up data from ransomware attack.

I have a folder which contains credential files of my google drive account (this folder is used by my script to authenticate itself to my google drive account)

My question is that, as ransomware is capable of affecting network drives and data which is sync’d via cloud, could it possibly use those credential’s stored on my pc to gain access to my drive account and start affecting my files over there?