Microsoft 365 Security Assessment: What Businesses Should Check Before Problems Occur

Microsoft 365 plays a central role in how businesses communicate, collaborate, and manage information. From Outlook and Teams to SharePoint and OneDrive, organizations rely on these tools to keep employees connected and operations running efficiently. However, simply using Microsoft 365 does not guarantee that an organization's environment is properly secured.

Security settings, user permissions, authentication policies, and data-sharing configurations all influence how well Microsoft 365 protects business information. Without regular reviews, overlooked settings and outdated permissions can create vulnerabilities that put sensitive data at risk.

A Microsoft 365 security assessment helps businesses identify these weaknesses before they lead to security incidents. By reviewing how Microsoft 365 is configured, organizations can strengthen protection, improve compliance readiness, and establish better control over their technology environment.

What Is a Microsoft 365 Security Assessment?

A Microsoft 365 security assessment is a structured review of an organization's Microsoft 365 environment to identify security gaps, configuration weaknesses, and opportunities for improvement.

The assessment examines how users access company resources, how sensitive information is protected, and whether security controls align with the organization's operational needs.

Unlike basic troubleshooting, which focuses on resolving immediate technical problems, a security assessment evaluates the broader environment to uncover risks that may not be immediately visible.

Businesses working with an experienced IT provider can use assessment findings to prioritize improvements and establish more consistent security practices. CBM IT's Microsoft 365 solutions can support organizations looking to improve how they manage and secure their Microsoft environment.

Why Microsoft 365 Security Assessments Matter

Microsoft provides numerous built-in security capabilities, but organizations are responsible for configuring and managing many of these protections.

As businesses grow, employees change roles, new applications are introduced, and access requirements evolve. Security settings that were appropriate during an initial deployment may no longer reflect the organization's current needs.

For example, former employees may retain active accounts, administrators may have unnecessary privileges, or external sharing permissions may allow information to reach unintended recipients.

Regular assessments help organizations identify these issues while supporting broader cybersecurity and technology management goals.

7 Areas Every Microsoft 365 Security Assessment Should Cover

1. Multifactor Authentication and Conditional Access

Passwords alone are not sufficient to protect business accounts against modern cyber threats. Multifactor authentication (MFA) adds another verification requirement, making unauthorized access more difficult.

A security assessment should verify that MFA is appropriately enforced, particularly for administrative accounts and users accessing sensitive information.

Organizations should also evaluate Microsoft Entra Conditional Access policies, which can control access based on factors such as user identity, device compliance, and sign-in risk.

These controls help businesses establish stronger authentication practices without unnecessarily disrupting employee productivity.

2. User Permissions and Administrative Access

Employees need access to the applications and information required for their responsibilities. However, granting excessive permissions increases the potential impact of compromised accounts.

A Microsoft 365 security assessment should review administrator roles, shared account access, inactive users, and permissions assigned to employees who have changed positions.

Organizations should follow the principle of least privilege, giving users only the access necessary to perform their jobs.

Regular access reviews also help businesses maintain accountability and reduce unnecessary exposure across their Microsoft 365 environment.

3. Email Security and Phishing Protection

Email remains a common entry point for cyberattacks. Phishing messages, malicious attachments, and impersonation attempts can expose credentials or compromise business communications.

A security assessment should examine Microsoft 365 email protection settings, including anti-phishing policies, spam filtering, attachment scanning, and suspicious message handling.

Businesses should also review email authentication configurations, including SPF, DKIM, and DMARC, to help protect their domains against spoofing.

Combining technical protections with employee security awareness training provides a more comprehensive defense against email-based threats.

4. SharePoint and OneDrive Sharing Permissions

SharePoint and OneDrive make it easy for employees to collaborate and share documents. However, overly permissive sharing settings can unintentionally expose confidential information.

An assessment should evaluate external sharing policies, anonymous links, guest access, and permissions associated with sensitive document libraries.

Businesses should determine whether employees can share files outside the organization and whether those permissions align with internal security policies.

Reviewing these configurations helps organizations maintain collaboration while establishing appropriate boundaries around business information.

5. Microsoft Defender Security Settings

Microsoft Defender provides security capabilities that can help organizations detect and respond to suspicious activity. However, available protections depend on licensing and proper configuration.

A security assessment should review which Defender capabilities are enabled, how alerts are handled, and whether security policies reflect the organization's risk exposure.

Depending on licensing, this may include endpoint protection, identity monitoring, email threat detection, and automated investigation capabilities.

Businesses should also evaluate whether security alerts are consistently reviewed and whether responsibilities for responding to potential threats are clearly defined.

6. Audit Logging and Security Monitoring

Security logs provide valuable information about activity within Microsoft 365, including sign-ins, administrative changes, and access to business resources.

Without appropriate logging and monitoring, suspicious behavior may go unnoticed.

A Microsoft 365 security assessment should verify that relevant audit capabilities are enabled, retention settings meet organizational requirements, and security events can be investigated when necessary.

Organizations should also establish procedures for reviewing important alerts and escalating potential incidents.

CBM IT's cybersecurity services can help businesses take a broader approach to identifying technology risks and strengthening their security posture.

7. Data Retention and Compliance Configurations

Organizations often have requirements governing how business information is stored, retained, accessed, and deleted.

Microsoft 365 includes compliance and information governance capabilities, but these settings must be configured according to the organization's specific obligations. A security assessment should review retention policies, sensitive information protections, and controls governing access to regulated or confidential data.

Businesses should also confirm that existing policies align with their operational needs and applicable regulatory requirements.

For organizations managing complex requirements, technology compliance services can help connect technical controls with broader governance objectives.

Common Microsoft 365 Security Mistakes Businesses Overlook

Even organizations with established IT processes can overlook security weaknesses that develop gradually.

Common examples include inconsistent MFA enforcement, excessive administrative permissions, inactive user accounts, unrestricted external sharing, and security alerts that are not regularly reviewed.

Another frequent challenge involves assuming Microsoft automatically manages every aspect of security. While the platform provides extensive capabilities, organizations remain responsible for many identity, access, data protection, and configuration decisions.

Identifying these gaps through a structured assessment allows businesses to prioritize corrective actions instead of waiting until a security incident exposes weaknesses.

How Often Should Businesses Conduct a Microsoft 365 Security Assessment?

There is no universal assessment schedule that fits every organization. The appropriate frequency depends on factors such as company size, regulatory obligations, technology complexity, and overall risk exposure.

Many businesses benefit from conducting a comprehensive assessment annually, supported by more frequent reviews of critical security settings.

Additional assessments may be appropriate following major organizational changes, Microsoft 365 migrations, security incidents, or significant updates to access policies.

Ongoing monitoring and periodic configuration reviews help ensure that security controls remain effective as business requirements evolve.

How Managed IT Services Support Microsoft 365 Security

A security assessment provides valuable insight, but maintaining a secure environment requires continued attention.

Managed IT services can help businesses address identified weaknesses, review access permissions, maintain security configurations, and coordinate improvements as technology needs change.

Working with a provider also gives organizations access to technical expertise when evaluating new Microsoft 365 features, managing employee transitions, or responding to emerging security concerns.

CBM IT's managed IT services support organizations seeking more consistent technology management and a proactive approach to IT security.

Strengthen Your Microsoft 365 Security With CBM IT

Microsoft 365 security requires more than enabling a few protective settings.

Businesses need visibility into how their environment is configured, who can access sensitive resources, and whether existing controls continue to meet their needs.

A comprehensive security assessment provides a foundation for identifying risks, improving configurations, and making informed technology decisions.

CBM IT helps organizations manage their IT environments through Microsoft 365 solutions, cybersecurity services, and ongoing technology support.

Contact CBM IT to discuss your Microsoft 365 environment and explore opportunities to strengthen your organization's security.