With automated rejection of embedded files with questionable extensions, Microsoft has promised increased security for OneNote users. OneNote is a part of the Office suite that is frequently used by business users for task management and taking notes. It also offers multi-user collaboration features among other things.
Like other Office programmes, OneNote has been misused to spread malware, particularly because OneNote documents allow attackers to attach files that would be executed with little to no user notification. Users were specifically given the choice to ignore the warning and open the embedded file right away while being advised that opening a OneNote attachment might be dangerous.