Microsoft 365 Security Hardening & Protection
Microsoft 365 is the backbone of your business — email, files, collaboration, and identity all live in one platform. But Microsoft's default security settings leave critical gaps that attackers exploit daily. Petronella Technology Group hardens your M365 environment with enterprise-grade configurations, advanced threat protection, and continuous monitoring that goes far beyond what Microsoft provides out of the box.
Conditional Access • Defender for Office 365 • DLP • Azure AD Hardening • SharePoint Security • Teams Governance • Entra ID
Q: Why is Microsoft 365 security hardening necessary? Microsoft 365's default configurations prioritize ease of use over security. Out of the box, MFA may not be enforced, legacy authentication protocols remain enabled, external sharing in SharePoint and OneDrive is unrestricted, and email forwarding rules are unmonitored. These defaults are exactly what attackers exploit in business email compromise, account takeover, and data exfiltration attacks. PTG closes these gaps. Schedule a free M365 security review →
Why Default Microsoft 365 Settings Put You at Risk
Common Microsoft 365 Security Gaps PTG Closes
Multi-factor authentication not enforced for all accounts. Legacy authentication protocols still enabled (allowing password spray attacks). No conditional access policies controlling where and how users sign in. External email forwarding rules silently exfiltrating data. Overly permissive SharePoint and OneDrive external sharing. Unmonitored OAuth app permissions granting third-party access to your data. No data loss prevention policies protecting sensitive information. Audit logging disabled or not monitored. Admin accounts without privileged access management. PTG addresses every one of these gaps in our hardening engagement.
Microsoft 365 Security Hardening Services
PTG's M365 security hardening covers every component of your Microsoft tenant — from identity and email to collaboration tools and data protection.
Entra ID (Azure AD) & Conditional Access
PTG configures Entra ID with security-first policies: MFA enforcement for all users, conditional access policies based on location, device compliance, and risk level, legacy authentication blocking, privileged identity management for admin accounts, and automated access reviews. We implement break-glass emergency access accounts, configure sign-in risk policies, and deploy passwordless authentication options for enhanced security with reduced user friction.
Exchange Online & Defender for Office 365
Harden your email security beyond default Exchange Online Protection: Safe Attachments with dynamic delivery, Safe Links with time-of-click verification, anti-phishing policies with impersonation protection for executives and partners, anti-spam tuning, mail flow rule audit and remediation, external sender tagging, and automated investigation and response. See our dedicated email security services for the full stack.
SharePoint, OneDrive & Teams Governance
Restrict external sharing to approved domains, configure sensitivity labels for document classification, implement DLP policies that prevent sensitive data from being shared outside the organization, audit existing sharing links and remediate overly permissive access, configure Teams meeting policies and guest access controls, and establish information barriers for organizations handling confidential client data across teams.
Data Loss Prevention (DLP)
Configure Microsoft Purview DLP policies across Exchange, SharePoint, OneDrive, and Teams to detect and block sensitive data exposure. PTG builds custom DLP rules for your specific data types — credit card numbers, Social Security numbers, PHI, CUI, client confidential information — with policy actions ranging from user notifications to automatic encryption to blocking. DLP policy tuning reduces false positives while ensuring genuine sensitive data never leaves your control.
Security Monitoring & Incident Response
Enable unified audit logging across all M365 workloads, configure alert policies for suspicious activities (impossible travel, mass file downloads, admin account changes), integrate M365 security signals with your SIEM or PTG's managed security operations center, and establish incident response playbooks for M365-specific attack scenarios including account takeover, business email compromise, and data exfiltration through OneDrive or Teams.
Microsoft Secure Score Optimization
Microsoft Secure Score measures your M365 security posture against recommended configurations. Most organizations score below 50% out of the box. PTG systematically implements the recommended actions that improve your score, prioritizing by risk impact and business feasibility. We target a Secure Score above 80% for all clients, with clear documentation of any recommendations intentionally deferred and the risk acceptance rationale. Quarterly reviews ensure your score stays high as Microsoft adds new recommendations.
M365 Security for Compliance Requirements
PTG's M365 hardening satisfies the cloud security and access control requirements of major compliance frameworks.
CMMC & NIST 800-171
Conditional access policies, CUI protection in SharePoint and email, audit logging for all CUI access, MFA enforcement, and data loss prevention controls that satisfy CMMC Level 2 requirements for cloud environments. PTG ensures your M365 tenant meets CMMC compliance requirements for organizations handling Controlled Unclassified Information.
HIPAA
Email encryption for ePHI, access controls and audit logging for Teams and SharePoint sites containing patient data, DLP policies preventing PHI exposure, and Business Associate Agreement compliance with Microsoft. PTG configures your M365 environment to satisfy HIPAA Security Rule requirements for cloud-hosted protected health information.
SOC 2 & ISO 27001
Access control evidence, change management documentation, security monitoring configurations, and data protection controls that map to SOC 2 Trust Service Criteria and ISO 27001 Annex A controls. PTG generates compliance evidence from your M365 configuration that auditors accept.
PCI DSS 4.0
Prevent cardholder data from being stored or transmitted through M365 services, enforce strong authentication for accounts with access to payment systems, and configure DLP policies that detect and block PAN data in email, Teams, and SharePoint. M365 hardening supports PCI DSS compliance for organizations processing card payments.
Microsoft 365 Security Questions, Answered
What is included in a Microsoft 365 security assessment?
PTG's free M365 security assessment reviews your current Secure Score, conditional access policy configuration, MFA enforcement status, legacy authentication exposure, external sharing settings, mail flow rules (checking for malicious forwarding), OAuth app permissions, admin account security, audit logging status, and DLP policy coverage. We deliver a prioritized remediation report with specific configuration changes ranked by risk impact.
Will M365 hardening disrupt our day-to-day operations?
PTG implements hardening changes in a controlled, phased manner with advance communication to your users. MFA enrollment is scheduled with adequate lead time and user support. Conditional access policies are deployed in report-only mode first to identify potential impact before enforcement. DLP policies start in monitor-only mode to tune false positives. Our goal is zero disruption to legitimate business operations while closing security gaps that attackers exploit.
Do we need Microsoft E5 licenses for full security?
Many critical security features are available in Microsoft 365 Business Premium and E3 licenses, including MFA, conditional access, and basic DLP. However, E5 or add-on licenses unlock advanced capabilities like Defender for Office 365 Plan 2, Microsoft Defender for Endpoint, advanced eDiscovery, insider risk management, and automated investigation and response. PTG evaluates your current licensing and recommends the most cost-effective approach to achieve your security and compliance goals.
How do you handle Microsoft 365 security for remote workers?
Remote work makes M365 security hardening even more critical. PTG configures conditional access policies that evaluate user risk based on location, device compliance, and sign-in behavior. We implement device-based access controls that require managed or compliant devices for sensitive data access, configure session controls that limit what users can do from unmanaged devices, and deploy app protection policies for mobile devices. The result is secure remote access without VPN dependency.
Can PTG manage our M365 security on an ongoing basis?
Yes. After initial hardening, PTG offers ongoing M365 security management through our managed security services (MSSP) or vCISO engagements. This includes continuous Secure Score monitoring, security alert triage and investigation, policy maintenance as Microsoft releases new features and recommendations, quarterly security posture reviews, and incident response for M365-specific threats.
What is Microsoft Secure Score and why does it matter?
Microsoft Secure Score is a measurement of your M365 tenant's security posture, scored against Microsoft's recommended security configurations. Most organizations score below 50% with default settings. PTG targets Secure Scores above 80%, implementing the recommended actions that deliver the highest security impact. A higher Secure Score reduces your attack surface, satisfies compliance requirements, and may improve your cyber insurance terms. We document all implemented and deferred recommendations for audit and governance purposes.
Harden Your Microsoft 365 Environment Today
Schedule a free Microsoft 365 security assessment with PTG. We will evaluate your current configuration, identify the gaps attackers are most likely to exploit, and deliver a prioritized remediation plan — all at no cost.
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