Microsoft finally fixes one of the biggest Windows security threats

Microsoft has shared more details about a major security update for OneNote, with which it hopes to address the growing problem that its program is increasingly being used to push ransomware and other types of malware.

In a new Microsoft 365 support document, the company listed a total of 120 file extensions that will soon be blocked in OneNote. Among the file types are . XLL, . ISO, .BAT and .JS stand out.

These extensions are also blocked in other
Office 365
programs such as Outlook, Word, Excel or PowerPoint.

Block files

While previously opening a OneNote file with a suspicious attachment would trigger a warning message, the new update prevents the file from being opened – at all. Instead, the user gets a warning window saying “Your administrator has blocked your ability to open this file type in OneNote.”

The changes will roll out version 2304 in Current Channel (Preview) to OneNote for Microsoft 365, on Windows devices, in April or May this year, it said. Retail versions of Office 2021, Office 2019 and Office 2016 (current channel) will also be updated to reflect these changes, but volume licensed versions of Office (Office Standard 2019 or OFfice LTSC Professional Plus 2021) will not receive the update.

The changes will roll out version 2304 in Current Channel (Preview) to OneNote for Microsoft 365, on Windows devices, in April or May this year, it said. Retail versions of Office 2021, Office 2019 and Office 2016 (current channel) will also be updated to reflect these changes, but volume licensed versions of Office (Office Standard 2019 or OFfice LTSC Professional Plus 2021) will not receive the update.

Source: BleepingComputer