Microsoft Copilot for M365 Readiness Assessment Framework

Microsoft Copilot for Microsoft 365 represents a significant shift in how organizations interact with their data. For security teams and CISOs, ensuring proper readiness before deployment is critical to maintaining security posture and regulatory compliance. This technical framework provides a comprehensive methodology and automated assessment tools to evaluate your organization's readiness for Microsoft Copilot.

Why Readiness Assessment Matters

Microsoft Copilot surfaces content based on user permissions and access rights. Without proper security controls, Copilot can expose sensitive information, violate compliance requirements, and create significant risk. A thorough readiness assessment identifies gaps before deployment, enabling proactive remediation.

Critical Risk Areas

• Data Oversharing: Copilot can access and surface content shared with overly broad permissions
• Missing Sensitivity Labels: Unlabeled sensitive data may be exposed through Copilot responses
• External User Access: External users with access can query data via Copilot
• Inadequate Conditional Access: Weak authentication and device controls increase risk
• Compliance Gaps: Regulatory requirements may not be met without proper controls

Six Assessment Dimensions

The framework evaluates readiness across six critical dimensions:

1. Information Protection & Sensitivity Labels

Critical for Copilot: Copilot respects sensitivity labels and applies protection to labeled content. Unlabeled sensitive data cannot be protected by Copilot.

Assessment Focus:

• Sensitivity label coverage across tenant
• Auto-labeling policy effectiveness
• Label distribution and usage patterns
• Unlabeled sensitive content identification

Readiness Thresholds:

• 80%+ coverage: Ready for Copilot deployment
• 60-79% coverage: Nearly ready, requires remediation
• 40-59% coverage: Significant work required
• <40% coverage: Not ready, major remediation needed

2. Data Sharing & Permissions

Critical for Copilot: Copilot surfaces content based on user permissions. Overshared content becomes accessible through Copilot queries.

Assessment Focus:

• Content shared with "Everyone" or "Everyone except external"
• Anonymous/Anyone sharing links
• Large security group shares
• Risk-scored oversharing instances

Key Metrics:

• Percentage of overshared content
• High-risk sharing instances
• OneDrive vs SharePoint sharing patterns

3. External User Access

Critical for Copilot: External users with tenant access can query organizational data through Copilot, creating regulatory and security concerns.

Assessment Focus:

• All external users with tenant access
• Sites and content accessible to external users
• Permission levels granted
• Inactive external accounts (>90 days)
• Risk scoring by access level

Regulatory Concerns:

• Financial services: External access to AI tools may violate regulations
• Healthcare: HIPAA concerns with external user access
• Government: Security clearance and access control requirements

4. Conditional Access Policies

Critical for Copilot: MFA and device compliance are essential for AI tool access. Inadequate CA policies create significant security risk.

Assessment Focus:

• MFA enforcement for Copilot apps
• Device compliance requirements
• Copilot app blocking risks
• Session control compatibility
• Zero Trust policy alignment

Required Policies:

• MFA required for Microsoft 365 Copilot apps
• Device compliance for Copilot access
• Location-based restrictions (if applicable)
• Session controls for Copilot sessions

5. Zero Trust Security Posture

Critical for Copilot: Zero Trust principles must be applied to Copilot to ensure secure access and data protection.

Assessment Focus:

• Identity verification (MFA, risk-based authentication)
• Device compliance and health
• Application access controls
• Data protection and encryption
• Network segmentation (if applicable)

6. Compliance & Governance

Critical for Copilot: Regulatory compliance must be maintained when deploying AI tools that access organizational data.

Assessment Focus:

• Regulatory framework alignment (GDPR, HIPAA, SOX, etc.)
• Data residency and sovereignty
• Audit logging and monitoring
• Policy enforcement mechanisms
• Governance structure and processes

PowerShell Assessment Scripts

The framework includes four automated PowerShell scripts for data collection and analysis. These scripts provide objective, quantifiable assessment data.

Script 1: Get-OversharedContent.ps1

Purpose: Identifies SharePoint and OneDrive content with overly broad permissions that pose risk when accessed through Copilot.

What It Analyzes:

• Content shared with "Everyone" or "Everyone except external"
• Anonymous/Anyone sharing links
• Large security group shares (>1000 members)
• Risk-scored oversharing instances

Usage:

.\Get-OversharedContent.ps1 -TenantUrl "https://contoso-admin.sharepoint.com" -OutputPath "C:\Reports\" -IncludeOneDrive

Outputs:

• OversharedContent_[timestamp].csv - Detailed findings with risk scores
• Summary statistics with risk level breakdowns
• Site-level and content-level analysis

Key Metrics:

• Total overshared items
• High-risk items (sensitive content with broad sharing)
• Percentage of tenant content overshared
• Sites with highest oversharing rates

Script 2: Get-LabelCoverage.ps1

Purpose: Calculates sensitivity label coverage across the tenant to assess information protection readiness.

What It Analyzes:

• Percentage of documents with applied labels
• Label distribution (Confidential, Internal, Public, etc.)
• Auto-labeling policy effectiveness
• Unlabeled sensitive content identification

Usage:

.\Get-LabelCoverage.ps1 -TenantUrl "https://contoso-admin.sharepoint.com" -SampleSize 1000

Outputs:

• LabelCoverage_[timestamp].csv - Document-level detail
• LabelDistribution_[timestamp].csv - Label type breakdown
• LabelCoverage_Summary_[timestamp].txt - Executive summary
• UnlabeledSensitiveContent_[timestamp].csv - High-risk findings

Readiness Scoring:

• 80%+ coverage: Ready for Copilot
• 60-79% coverage: Nearly ready
• 40-59% coverage: Requires work
• <40% coverage: Not ready

Script 3: Get-ExternalUserAccess.ps1

Purpose: Audits all external users and their access permissions to identify Copilot-related risks.

What It Analyzes:

• All external users with tenant access
• Sites and content they can access
• Permission levels granted (Read, Edit, Full Control)
• Inactive external accounts (>90 days)
• Risk scoring by access level

Usage:

.\Get-ExternalUserAccess.ps1 -TenantUrl "https://contoso-admin.sharepoint.com" -OutputPath "C:\Reports\"

Outputs:

• ExternalUserAccess_[timestamp].csv - Detailed access log
• ExternalUserSummary_[timestamp].csv - Per-user summary
• HighRiskExternalAccess_[timestamp].csv - Critical findings
• ExternalUserAccess_ExecutiveSummary_[timestamp].txt - Overview

Risk Categories:

• Critical: External users with Full Control on sensitive sites
• High: External users with Edit access to confidential content
• Medium: External users with Read access to internal content
• Low: External users with limited, appropriate access

Script 4: Get-CAPolicies.ps1

Purpose: Reviews Conditional Access policies for Copilot compatibility and security effectiveness.

What It Analyzes:

• Existing CA policy configuration
• MFA enforcement status
• Device compliance requirements
• Copilot app blocking risks
• Session control compatibility
• Zero Trust alignment

Usage:

.\Get-CAPolicies.ps1 -OutputPath "C:\Reports\" -CheckCopilotApps

Outputs:

• CA_PolicyAnalysis_[timestamp].csv - Full policy review
• CA_CompatibilityIssues_[timestamp].csv - Problem policies
• CA_RecommendedCopilotPolicies_[timestamp].csv - Implementation guide
• CA_ExecutiveSummary_[timestamp].txt - Executive overview

Required Policy Checks:

• MFA required for Microsoft 365 Copilot application
• Device compliance requirement
• Block legacy authentication
• Session controls configured
• Risk-based conditional access

Assessment Methodology

Phase 1: Discovery (Week 1)

Objective: Understand current state and collect baseline data.

Activities:

1. Run all four PowerShell assessment scripts
2. Collect existing policy documentation
3. Interview key stakeholders (IT, Security, Compliance)
4. Review current security controls
5. Document organizational structure

Deliverables:

• Baseline assessment data
• Current state documentation
• Stakeholder interview summaries

Phase 2: Analysis (Week 2)

Objective: Analyze assessment data and identify gaps.

Activities:

1. Analyze script outputs and identify patterns
2. Map findings to Copilot requirements
3. Risk assessment and prioritization
4. Gap analysis against best practices
5. Compliance requirement mapping

Deliverables:

• Gap analysis report
• Risk assessment matrix
• Compliance mapping document

Phase 3: Planning (Week 3)

Objective: Develop remediation roadmap and recommendations.

Activities:

1. Prioritize remediation activities
2. Develop implementation timeline
3. Resource requirement estimation
4. Dependency identification
5. Success criteria definition

Deliverables:

• Remediation roadmap
• Implementation plan
• Resource allocation plan

Phase 4: Reporting (Week 4)

Objective: Compile findings and recommendations into deliverable reports.

Activities:

1. Executive summary compilation
2. Technical findings documentation
3. Remediation roadmap finalization
4. Presentation preparation
5. Stakeholder review

Deliverables:

• Executive Readiness Report
• Technical Findings Report
• Remediation Roadmap
• Implementation Playbook

Technical Requirements

Prerequisites

PowerShell Modules Required:

Install-Module -Name Microsoft.Online.SharePoint.PowerShell
Install-Module -Name PnP.PowerShell
Install-Module -Name Microsoft.Graph.Identity.SignIns
Install-Module -Name Microsoft.Graph.Users

Permissions Needed:

• SharePoint Online Administrator
• Global Reader (minimum)
• Conditional Access Administrator (for CA policy review)
• Microsoft Graph API permissions:
  • Sites.Read.All
  • User.Read.All
  • Policy.Read.All
  • Directory.Read.All

Script Execution Environment

• PowerShell Version: 5.1 or PowerShell 7+
• Operating System: Windows 10/11, Windows Server 2016+
• Network: Connectivity to Microsoft 365 services
• Storage: Sufficient space for CSV outputs (varies by tenant size)

Framework Availability

The complete Microsoft Copilot Readiness Assessment Framework, including all four PowerShell assessment scripts and the comprehensive framework document, is available as an open-source project on GitHub:

GitHub Repository: https://github.com/nitrondigital/Microsoft-Copilot-Readiness-Framework

The repository includes:

• Professional framework document (20+ pages)
• Four PowerShell assessment scripts
• Usage documentation
• Example outputs
• Best practices and recommendations

Key Assessment Metrics

Overall Readiness Score

Calculate readiness across all six dimensions:

1. Information Protection: Label coverage percentage
2. Data Sharing: Overshared content percentage
3. External Access: Risk-scored external user access
4. Conditional Access: Policy coverage and effectiveness
5. Zero Trust: Alignment with Zero Trust principles
6. Compliance: Regulatory requirement coverage

Scoring Model:

• 5 (Ready): All dimensions meet readiness thresholds
• 4 (Nearly Ready): Minor gaps, quick remediation possible
• 3 (Requires Work): Moderate gaps, 2-4 weeks remediation
• 2 (Significant Work): Major gaps, 1-3 months remediation
• 1 (Not Ready): Critical gaps, 3+ months remediation

Critical Findings to Address

High Priority (Before Copilot Deployment)

1. Sensitivity Label Coverage <60%

   • Risk: Unlabeled sensitive data exposed through Copilot
   • Action: Implement auto-labeling policies and manual labeling program

2. Overshared Content >10%

   • Risk: Broadly shared content accessible via Copilot
   • Action: Review and restrict sharing permissions

3. External Users with Full Control

   • Risk: External users can query organizational data via Copilot
   • Action: Review and restrict external user permissions

4. No MFA for Copilot Apps

   • Risk: Unauthorized access to Copilot
   • Action: Implement Conditional Access policy requiring MFA

Medium Priority (Within 30 Days)

1. Device Compliance Not Required

   • Risk: Unmanaged devices accessing Copilot
   • Action: Implement device compliance requirements

2. Inactive External Accounts

   • Risk: Unused external access creating attack surface
   • Action: Review and remove inactive external users

3. Missing Auto-Labeling Policies

   • Risk: New content not automatically protected
   • Action: Deploy auto-labeling policies for sensitive content

Best Practices for Copilot Readiness

Information Protection

• Target 80%+ label coverage before Copilot deployment
• Implement auto-labeling policies for sensitive content types
• Use default sensitivity labels for consistent protection
• Enable sensitivity labels in Office apps

Data Sharing

• Review and restrict "Everyone" sharing
• Disable anonymous sharing for sensitive sites
• Implement sharing link expiration
• Regular access reviews for shared content

External Access

• Minimize external user access
• Use guest access with appropriate restrictions
• Regular review of external user permissions
• Remove inactive external accounts

Conditional Access

• Require MFA for all Copilot app access
• Enforce device compliance
• Block legacy authentication
• Implement session controls

Zero Trust

• Verify explicitly (MFA, risk-based authentication)
• Use least privilege access
• Assume breach (monitoring and detection)
• Encrypt data in transit and at rest

Conclusion

A comprehensive readiness assessment is essential before deploying Microsoft Copilot for M365. The framework and PowerShell scripts provided enable security teams and CISOs to objectively evaluate readiness, identify gaps, and develop remediation plans. By addressing critical security and compliance gaps before deployment, organizations can safely leverage Copilot's capabilities while maintaining security posture and regulatory compliance.

The automated assessment scripts provide quantifiable data to support decision-making and track remediation progress. Regular reassessment ensures ongoing readiness as organizational data and access patterns evolve.

Next Steps:

1. Download the framework and scripts from the GitHub repository
2. Run the assessment scripts in your environment
3. Analyze findings and prioritize remediation
4. Implement recommended security controls
5. Reassess readiness before Copilot deployment

For questions or support with the framework, refer to the repository documentation or contact the framework maintainers.