Microsoft Teams: Customize blocked file extensions for Weaponizable File Protection

🚨 The Signal: Teams now allows customisation of blocked file extensions for weaponizable file protection. This enhances an organisation's ability to tailor security policies, reducing risk from malicious file types.

The Impact

Security teams and Teams administrators are affected, gaining granular control to mitigate risks from weaponizable file types.

• Security Teams: Can enforce stricter file type controls, reducing malware risk.
• Teams Administrators: Gain flexibility to customise blocked file lists, improving security posture.
• End Users: May experience fewer legitimate files being blocked, improving collaboration.
• Compliance Officers: Can better demonstrate adherence to data handling and content filtering policies.

The Action

1. Review existing Teams file sharing policies for alignment with organisational security standards.
2. Navigate to Microsoft Teams admin center > Messaging policies.
3. Identify or create a policy for weaponizable file protection.
4. Customise the list of blocked file extensions to meet specific security requirements.
5. Test the updated policy to ensure expected behaviour and minimal user disruption.

Domain: Teams · Impact: high · Workload: Teams · Essential Eight: Application Control · ISM: ISM-0843, ISM-1490, ISM-1544, ISM-1582, ISM-1656, ISM-1657, ISM-1658, ISM-1659, ISM-1660, ISM-1870, ISM-1871