Microsoft 365 Security Settings Every Business Should Enable

Most businesses using Microsoft 365 are paying for advanced security tools they never activate. It's like buying a car with airbags and seat belts but never buckling up. The tools are there, you just need to configure them.

Configuration #1: Multi-Factor Authentication (MFA)

Priority: CRITICAL

MFA is the most effective security measure that exists. It blocks 99.9% of compromised credential attacks.

How to activate: Microsoft 365 admin center → Security → Multi-factor authentication → Enable for all users.

Recommendation: Use Microsoft Authenticator as the primary method (more secure than SMS). Configure backup methods for emergencies.

Common resistance: "My employees will complain." The reality is the app only asks for verification when it detects access from a new location or unrecognized device. In day-to-day use, it's transparent.

Configuration #2: Security Defaults

Priority: HIGH

If you don't have Azure AD Premium, Security Defaults is your best option. It automatically enables:

• MFA for all administrators
• MFA for all users (when necessary)
• Blocking of legacy authentication protocols (which are vulnerable)
• Protection of privileged actions

How to activate: Azure Active Directory → Properties → Manage Security Defaults → Yes.

Configuration #3: Conditional Access (requires Azure AD Premium)

If you have Azure AD Premium P1 or P2, Conditional Access replaces Security Defaults with granular policies:

• Policy 1: Require MFA when accessing from outside the office network
• Policy 2: Block access from countries where you don't operate
• Policy 3: Require managed device to access sensitive data
• Policy 4: Force password change when account risk is detected

Configuration #4: Microsoft Defender for Office 365

Included in: Microsoft 365 Business Premium, E5

Defender protects against advanced phishing, malware, and targeted attacks:

Safe Attachments: Opens email attachments in an isolated sandbox before delivering to the user. If the file attempts to execute malicious code, it's blocked.

Safe Links: Rewrites URLs in emails to verify them at click time (not just at delivery time). Protects against URLs that are clean at send time but become malicious later.

Anti-phishing policies: Detects impersonation attempts of your company executives (an attacker posing as your CEO to request wire transfers).

How to configure: Security center → Threat policies → Configure each policy.

Configuration #5: Information Protection

Data Loss Prevention (DLP): Prevents sensitive data from accidentally leaving your organization:

• Detects credit card numbers, RFCs, CURPs in emails and documents
• Blocks or warns before sending sensitive information externally
• Works across Exchange, SharePoint, OneDrive, and Teams

Sensitivity Labels: Tag documents as "Confidential", "Internal", "Public" and apply automatic protection:

• Confidential documents are automatically encrypted
• Only authorized people can open labeled documents
• Protection travels with the document (even outside your organization)

Configuration #6: Auditing and Monitoring

Unified Audit Log: Records ALL activity in your Microsoft 365 tenant:

• Who accessed what file, when
• Failed login attempts
• Permission changes
• Data deletion

Activate at: Compliance center → Audit → Turn on.

Alert Policies: Configure automatic alerts for:

• Multiple failed login attempts
• Access from unusual locations
• Mass file deletion
• Changes to email rules (attackers create rules to forward emails)

Configuration #7: Device Management (Intune)

Included in: Microsoft 365 Business Premium

Intune lets you control which devices access corporate data:

• Compliance policies: Only devices with active antivirus, encryption, and PIN can access
• Remote wipe: If an employee loses their phone, you can remotely wipe corporate data
• App protection: Work data is stored in an isolated container on personal devices

Implementation Checklist

Recommended order to implement these configurations:

1. MFA for all administrators (today)

2. Security Defaults or Conditional Access

3. Defender for Office 365 (Safe Attachments + Safe Links)

4. Unified Audit Log

5. Alert Policies

6. DLP policies

7. Sensitivity Labels

8. Intune (devices)

Estimated time: An experienced administrator can configure everything in 2-3 days. The longest part is communication and user training.

The Cost of Not Configuring

You're already paying for these tools. Not using them is wasting money and exposing yourself unnecessarily. 80% of breaches in companies using Microsoft 365 could have been prevented with configurations already available in their license.

At Simiriki, we configure and optimize your Microsoft 365 environment for maximum security with our Operation. We ensure every tool you're already paying for is working to protect your company. Start with an audit to see what you have disabled.