Microsoft 365 Security Audit

World Class Microsoft 365 Security Audit

Altius IT's Microsoft 365 security audit goes beyond basic checks. Our CISA-certified auditors conduct a comprehensive Microsoft 365 security assessment of your entire tenant to identify hidden misconfigurations, security gaps, and compliance blind spots that could expose your organization to cyber threats.

Most businesses rely on Microsoft 365 for email, collaboration, document storage, and communication, but default Microsoft 365 settings are not designed for maximum security. Misconfigurations in identity, sharing, and email policies leave organizations vulnerable to phishing attacks, account takeovers, business email compromise, and data breaches. Our thorough security assessment process ensures your Microsoft 365 environment is securely configured, properly monitored, and aligned with your compliance requirements.

Why a Microsoft 365 Security Assessment Is Critical

• Microsoft 365 is the #1 target for phishing attacks. Attackers specifically target Microsoft 365 users to steal credentials and bypass weak email protections. Without proper configuration, phishing emails often reach user inboxes undetected.
• Stolen credentials enable silent account takeovers. Compromised passwords allow attackers to log in without triggering alerts or suspicion. Lack of MFA and conditional access makes these attacks extremely effective.
• Business email compromise causes financial fraud. Threat actors impersonate executives and vendors to redirect payments or steal sensitive data. These attacks often bypass basic spam filtering and exploit trusted email relationships.
• Misconfigured security settings create hidden exposure. Default Microsoft 365 settings leave identity, sharing, and email policies in a weak state. Organizations often don't realize they are exposed until after an incident.
• Compliance failures lead to fines and data breaches. Improper data protection and logging can result in regulatory violations and audit failures under HIPAA, SOC 2, ISO 27001, PCI DSS, and other frameworks.

Identity and Access Management

• Multi-factor authentication (MFA): Enrollment status across all users, enforcement gaps, authentication method strength, and per-user vs. conditional access-based MFA configuration.
• Conditional access policies: Policy completeness, risk-based access rules, device compliance requirements, location-based restrictions, and session controls.
• Privileged Identity Management (PIM): Standing admin access review, just-in-time privilege elevation configuration, role activation requirements, and access reviews.
• User and role assessment: Excessive global admin assignments, stale and inactive accounts, guest user permissions, and least-privilege alignment.
• Authentication methods: Legacy authentication protocols, password policies, self-service password reset configuration, and sign-in risk policies.

Email Security and Anti-Phishing Protection

• SPF, DKIM, and DMARC configuration: Sender authentication validation, domain spoofing protection, and DMARC enforcement policy review.
• Microsoft Defender for Office 365: Safe Links, Safe Attachments, anti-phishing policies, impersonation protection, and zero-hour auto purge (ZAP) configuration.
• Exchange Online protection: Mail flow rules, transport rules, anti-spam policies, quarantine settings, and inbound/outbound filtering.
• Mailbox permissions and delegation: Send-as, send-on-behalf, full access delegations, forwarding rules, and inbox rule auditing for signs of compromise.
• External email handling: External sender identification tags, warning banners, and auto-forwarding restrictions.

Data Protection and Loss Prevention

• Data loss prevention (DLP) policies: Policy coverage across Exchange, SharePoint, OneDrive, and Teams. Sensitive information type detection, policy enforcement actions, and user notification settings.
• Sensitivity labels and information protection: Label taxonomy review, auto-labeling rules, encryption enforcement, and classification coverage across workloads.
• Retention policies and data governance: Retention labels, retention policies across mailboxes, SharePoint, and Teams. Litigation hold configuration and compliance search readiness.
• Encryption: Message encryption settings, rights management, and transport-level encryption enforcement.

External Sharing and Collaboration Security

• SharePoint and OneDrive sharing settings: External sharing levels, anonymous link policies, link expiration, and default sharing scope.
• Teams security: Guest access policies, meeting security settings, external communication controls, and channel-level permissions.
• Third-party app and OAuth permission review: Enterprise application consent, user-consented apps, risky API permissions, and app governance policies.

Audit Logging, Monitoring, and Alerting

• Unified audit log: Audit log enablement, retention period, and log coverage across all Microsoft 365 workloads.
• Alert policies: Default and custom alert policy review, notification routing, and alert response procedures.
• Sign-in logs and activity monitoring: Risky sign-in detection, impossible travel alerts, and anomalous activity monitoring configuration.
• Security and compliance center: Microsoft Secure Score review, baseline comparison, and compliance manager posture assessment.

Endpoint and Device Access Controls

• Microsoft Intune policies: Device compliance policies, conditional access integration, app protection policies, and device enrollment restrictions.
• Device access controls: Managed vs. unmanaged device access, browser-only restrictions, and mobile application management settings.

Tenant Baseline and Secure Configuration

• Tenant security baseline: Microsoft 365 default settings compared against CIS Microsoft 365 Foundations Benchmark and Microsoft security best practices.
• Microsoft Secure Score: Current score analysis, improvement action prioritization, and comparison against industry averages.
• Administrative settings: Global tenant settings, user consent policies, self-service configurations, and legacy feature disablement.

How This Differs From an IT Security Audit

An IT security audit evaluates your entire IT infrastructure, including servers, databases, cloud platforms, endpoints, and Microsoft 365 as one component among many. A dedicated Microsoft 365 security assessment goes deep on your M365 tenant specifically, covering every workload, policy, and configuration in detail. This is the right engagement if your organization relies heavily on Microsoft 365, has never had a dedicated M365 security assessment, or needs to address Microsoft 365-specific compliance requirements.

Who This Is For

A Microsoft 365 security assessment is the right engagement for any organization that relies on Microsoft 365 for email, file storage, collaboration, or communication. It is especially valuable for:

• Organizations that have never conducted a dedicated Microsoft 365 security assessment of their tenant
• Companies that have experienced phishing incidents, business email compromise, or account takeover attempts
• IT teams that have grown their Microsoft 365 deployment over time and are unsure if security settings have kept pace
• Organizations preparing for compliance audits requiring evidence of email security, access controls, and data protection (HIPAA, SOC 2, ISO 27001, PCI DSS, NIST, CMMC)
• Companies with remote or hybrid workforces where Microsoft 365 is the primary collaboration platform
• Organizations that have recently migrated to Microsoft 365 or upgraded licensing tiers and want to ensure all available security features are properly enabled

What You Receive

• Executive Summary: A non-technical overview of findings, overall risk rating, and strategic recommendations for leadership.
• Detailed Findings Report: Each misconfiguration and security gap documented with severity rating, evidence (configuration screenshots, policy status), and step-by-step remediation instructions.
• Microsoft Secure Score Analysis: Your current Secure Score benchmarked against industry averages, with a prioritized list of improvement actions.
• CIS Benchmark Comparison: Your tenant configuration mapped against the CIS Microsoft 365 Foundations Benchmark to identify gaps.
• Remediation Roadmap: A prioritized action plan organized by severity and effort, so your team knows exactly what to fix first.
• Risk-Rated Findings: Every finding classified as Critical, High, Medium, Low, or Informational, with clear business impact context.

Combine With Other Services

Our Microsoft 365 security assessment can be performed as a standalone engagement or combined with other Altius IT services for broader coverage:

• Black Box Penetration Test: Pair your M365 security review with a black box penetration test to validate whether your external-facing assets and network perimeter can withstand a real-world attack.
• Information Security Audit: Evaluate your Microsoft 365 security within the context of your overall security program, governance, and compliance framework.
• Cybersecurity Audit: Pair your M365 security review with penetration testing and threat defense evaluation for complete coverage of your attack surface.
• Compliance Audit: Use the M365 security audit findings as direct evidence for compliance requirements under HIPAA, SOC 2, ISO 27001, PCI DSS, and others.