Security Guide
Microsoft 365 Security Guide
Microsoft 365 is one of the most common targets for phishing, account compromise, and data exposure. This guide outlines practical steps to improve security for small and growing organizations.
MFA
Email Security
Conditional Access
Data Protection
Best Practice
Enable Multi-Factor Authentication
- Require MFA for all users, especially administrators.
- Use authenticator apps instead of SMS where possible.
- Disable legacy authentication protocols.
- Require MFA for remote or unfamiliar sign-ins.
Best Practice
Protect Email from Phishing
- Enable Microsoft Defender anti-phishing policies.
- Use Safe Links and Safe Attachments protections.
- Block automatic external forwarding.
- Train users to recognize suspicious emails.
Best Practice
Review Admin Access
- Limit the number of global administrators.
- Use separate accounts for admin privileges.
- Audit admin activity regularly.
- Remove unnecessary privileged roles.
Best Practice
Secure File Sharing
- Review SharePoint and OneDrive sharing settings.
- Restrict anonymous external sharing where possible.
- Monitor file access and sharing activity.
- Implement expiration for shared links.
Best Practice
Monitor Sign-In Activity
- Review sign-in logs regularly.
- Investigate unfamiliar login locations.
- Enable risky sign-in alerts.
- Use conditional access policies.
Best Practice
Protect Business Data
- Implement retention policies.
- Use data loss prevention policies.
- Back up Microsoft 365 data outside of Microsoft.
- Ensure recovery procedures are documented.