Information
Unauthorized changes to files can be made if permissions allow editing by anyone. By restricting permissions on links to **View** only, administrators prevent anonymous file changes.
Solution
1. Sign in to the SharePoint admin center.
2. Select Policies \> Sharing.
3. Scroll to the section Choose expiration and permissions options for Anyone links.
4. Set the configuration items in the section These links can give these permissions.
5. Set the Files option to View.
6. Set the Folders option to View.
7. Select Save.