Google Drive has a pretty bad spam problem, and it seems Google doesn’t care. Spammers can share files that automatically appear in your Drive, and there’s no way to stop it.
Update 1/4/19 10:10 AM CTS: Google got back to us with a statement saying that changes are coming to Drive’s sharing features and they’re “making it a priority.” Here’s the statement in full:
“For the vast majority of users, the default sharing permissions in Drive work as intended. Unfortunately, this was not the case for this user and we sincerely apologize for her experience. In light of this issue, we are evaluating changes to our spam, abuse, and blocking features that will prevent this kind of activity from taking place on Drive. In the interim, users who are experiencing similar issues can remove themselves from the folder, and the folder should not reappear in either “My Drive” or “Shared with Me” unless they revisit it.” — Google Spokesperson