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Microsoft 365 Security Assessment

Independent Technical Assurance

Know whether your Microsoft 365 controls are genuinely working — not just configured

Microsoft 365 is core to identity, collaboration and data,  and a prime target for attackers. Misconfiguration, over-permissive access and control gaps remain common contributors to compromise in Microsoft 365 environments.

Metis Security provides a Microsoft 365 Security Assessment designed to give you a clear, evidence-led view of how your tenant is performing in practice, and what matters most to address first. This assessment provides independent validation of Microsoft 365 security controls: confirming what is already effective, and identifying priority gaps where enforcement or coverage may fall short.

We go beyond surface-level checks. We evaluate identity and access enforcement, threat protection configuration, data protection controls and governance settings, combining technical analysis with risk-based prioritisation where required. The outcome is a focused, actionable view of your Microsoft 365 security posture and control effectiveness.

We focus on clarity over noise. You won’t receive a checklist or a generic scorecard — you’ll receive findings that explain what is wrong, why it matters, and what to do next.

Who this is typically for

This assessment is typically most valuable for organisations running Microsoft 365 as core operational infrastructure — professional services firms, technology companies and similar organisations that handle sensitive data but do not have a dedicated internal security function

This assessment is typically most valuable when:

  • Your Microsoft 365 environment has grown or evolved over time
  • There is reasonable confidence, but no recent independent validation
  • You need clear evidence to support internal assurance, prioritisation or decision-making

It is not intended as a tool-only audit or a compliance-led exercise. The focus is control effectiveness and configuration reality.

IDENTITY & ACCESS ENFORCEMENT

Most Microsoft 365 compromises begin with identity. This section confirms whether your authentication and access controls are enforcing the boundaries you believe they are. We assess Entra ID configuration, authentication controls and access governance to determine whether identity boundaries are properly enforced and resistant to abuse. Focus areas typically include:

  • Authentication strength and MFA enforcement consistency
  • Conditional Access design and policy interaction
  • Privileged Identity Management (PIM) configuration
  • Role assignments, delegation and least-privilege alignment
  • Guest and external access governance

THREAT PROTECTION & DETECTION READINESS

Having Microsoft Defender licensed is not the same as having it properly configured. We assess whether your threat protection controls are set up to generate meaningful signals and support a timely response:

  • Microsoft Defender configuration and coverage
  • Alerting, monitoring, and response capability
  • Logging and audit readiness
  • Visibility gaps that reduce detection effectiveness

DATA PROTECTION & EXPOSURE CONTROL

Sensitive data shared through Teams, SharePoint and OneDrive can be exposed in ways that are not immediately visible. We assess whether your data protection controls are actually limiting that exposure in practice:

  • Data classification and sensitivity labelling enforcement
  • DLP configuration and operational effectiveness
  • Information protection and rights management controls
  • External sharing governance and exposure pathways

GOVERNANCE & CONTROL CONSISTENCY

Controls that are configured correctly today can drift over time without consistent governance. We assess whether the structures that maintain your security posture are operating as intended.:

  • Policy design and enforcement consistency
  • Role and responsibility clarity
  • Monitoring and reporting alignment
  • Framework or regulatory alignment where required
How you will Gain

Benefits

Proactive Risk Reduction

Identify configuration gaps, privilege weaknesses and enforcement inconsistencies before they are exploited, reducing exposure to common Microsoft 365 attack paths.

Clear Control & Risk Insight

Understand where control gaps exist, why they matter, and what practical steps are required to address them.

Strengthened Control Effectiveness

Ensure identity, data protection and threat detection controls are not only enabled, but properly configured and consistently enforced.

Prioritised, Actionable Remediation

Receive risk-aligned recommendations focused on material improvement, not generic best-practice checklists.

Increased Operational Confidence

Gain clarity on how your tenant is actually configured and whether security assumptions reflect configuration reality.

Independent Technical Assurance

Benefit from specialist review grounded in real-world compromise patterns, delivering evidence-based conclusions rather than tool-driven output.

Validate Your Microsoft 365 Security Controls

Is your Microsoft 365 environment as secure as you think it is? A direct, no-obligation conversation with David is the practical starting point for finding out.
REQUEST AN M365 SECURITY ASSESSMENT
HOW WE HAVE HELPED IN THE PAST

Case Studies

Supporting Material

Blog Posts on M365 & Assessments

STREAMLINED AND EFFICIENT

Engagement Approach

M365 Security Assessment engagements are structured to deliver clear outcomes, not open-ended consultancy.

Initial Scoping

Define scope, objectives and rules of engagement, ensuring testing reflects real-world threat exposure and business priorities.

Controls Validation

Conduct structured assessment and impact validation across agreed in-scope systems.

Reporting & Technical Debrief

Document confirmed vulnerabilities, validated impact and prioritised remediation guidance with clear technical context.

Remediation & Re-Validation (Optional)

Where gaps are identified and support is required, practical guidance on remediation approach and validation of key fixes can be provided as an extension of the engagement.

COMPETITIVE AND BESPOKE

Engagement Scope & Depth

Microsoft 365 environments vary significantly in scale, architectural complexity and operational maturity. Meaningful security assessment requires scope aligned to identity structure, collaboration exposure, governance model and monitoring configuration. Engagements are structured to provide depth of analysis and defensible conclusions, not surface-level configuration review. A representative mid-sized tenant may include:

  • Entra ID with Conditional Access and PIM
  • Exchange Online, SharePoint, Teams and OneDrive
  • Defender for Office 365
  • Purview data protection controls
  • 50–500 users with varied role assignments

Larger or multi-tenant environments are scoped accordingly.

 

Microsoft 365 Control Validation

The most common starting point for organisations seeking independent validation of their Microsoft 365 security posture. A focused, fixed-scope engagement delivering clear findings and prioritised recommendations within a defined timeframe — without the overhead of a larger programme.
4 -5 days
  • Conditional Access design and enforcement
  • Privileged role and delegation configuration
  • Data protection and DLP effectiveness
  • Defender coverage and alert quality
  • Logging and audit readiness across core services

Extended Control & Governance Review

Builds on Control Validation to include governance maturity and operational alignment. Designed for environments requiring broader strategic assurance of Microsoft 365 security controls.
8-12 days
  • Control maturity assessment
  • Threat and exposure analysis
  • Governance and policy enforcement review
  • Change management and operational oversight evaluation
  • Framework alignment where required
  • Forward-looking security roadmap considerations

Complex & Multi-Tenant Engagements

For larger estates, multi-tenant structures or advanced requirements, scope is tailored to architectural complexity and operational needs.
Custom
  • Multiple Microsoft 365 tenants
  • Deep-dive reviews of Intune or endpoint controls
  • Advanced Defender configuration validation
  • Specialist service deep-dives
  • Extended framework or regulatory alignment

Engagement duration typically ranges from several days for focused validation to multi-week engagements for complex or multi-tenant environments. Final scope and pricing are confirmed following structured discovery discussion.

 

Start with a conversation

If you are responsible for Microsoft 365 in your organisation and want to know whether your controls are genuinely effective, a direct discussion with David is the most practical first step. No obligation, no sales process — just a clear conversation about your situation and whether an assessment would add value.
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