Who has access? I have sent files via GD to people, adding names as needed. Have you granted open access to anyone at all?
Not using GD more than once a month, I have not seen any spam, so I am a GD newb?
This is not about protecting the files you share, it's about spammers abusing the file sharing mechanism to send you notifications. THEY share a file with you in order to trigger a notification and there's no way to block this.
Ah, I see. Have never got one, fingers crossed. I am not a big user...
Based on the content in the article, you don't have to be a heavy user of Google Drive to see this sort of spam, nor do you have to send anyone files.