Utilize Private Channels
Block External Access
Limit Guest Access
Turn off File Sharing and File Storage Options
Block Third-Party Applications
Restrict Users who can Create Teams Channels
Set Teams Expiration
Set up Advanced Threat Protection Policies for Teams
Set up app Protection Policies
Set up Data Loss prevention Polcies
Additional Resources
- https://usc.pax8.com/resource/display/33588
- https://docs.microsoft.com/en-us/azure/active-directory/fundamentals/concept-fundamentals-security-defaults