Microsoft 365 Security: Features and Best Practices for Comprehensive Security and Enhanced Reliability

Microsoft 365 (M365), sometimes known as Microsoft Office 365 (O365), is a powerful cloud-based suite of productivity applications and services. These apps are ideal for organizations looking to be more productive, creative, and collaborative in a hassle-free, user-friendly manner.

Security is an important consideration for the Microsoft 365 platform. The many Office 365 security features enable organizations to safeguard their critical identities, data, files, and devices, from various cyberthreats and threat actors.

That said, these native features are not enough to defend your M365 environment.

• In 2022, 92% of organizations experienced phishing attacks in their Microsoft 365 environments.
• In 2023, daily cyberthreats targeting Office documents surged by 53%.
• In March 2024, Microsoft admitted that a cybercriminal group could leverage compromised Microsoft email accounts to ramp up their offensive measures against organizations.

These incidents show that effective Office 365 security requires an extra layer of security. This means investing in robust Office 365 security management practices and adopting time-tested O365 security best practices.

What Are the Built-in Security Features in Microsoft 365?

Microsoft 365 includes many built-in security features to protect your accounts, applications, and data from unauthorized access and breaches, including:

Microsoft Defender for Office 365

Previously known as Windows Defender Advanced Threat Protection (ATP),  Microsoft Defender for Office 365 is an integrated security operations platform that protects your assets and data against many types of threats, including credential phishing, malware, and ransomware. It includes extended detection and response (XDR) and security information and event management (SIEM) capabilities to help your organization:

• Prevent many types of volume-based and targeted cyberattacks 
• Respond quickly to sophisticated cyberattacks
• Remediate incidents with built-in automation
• Hunt for threats across the entire cyberattack chain
• Get data-driven insights to plug security blind spots and enhance your security posture

Microsoft 365 Security and Compliance Center

The Microsoft 365 Security and Compliance Center was a centralized portal that enabled organizations to protect their M365 services and achieve compliance with data-handling regulations. The portal is now part of the Microsoft Defender portal for managing security across 365 apps, devices, email, identities, and data.

Microsoft Defender for Cloud Apps

Microsoft Defender for Cloud Apps, previously known as Microsoft Cloud Apps Security (MCAS), helps to protect SaaS apps against many kinds of cyberthreats. It empowers organizations to:

• Get full visibility into their SaaS environment
• Apply real-time controls and automated processes to protect sensitive information in SaaS apps
• Hunt for sophisticated threats using scenario-based detections
• Investigate and address security configuration gaps
• Minimize the security risks of shadow IT

Microsoft Purview Data Loss Prevention (DLP)

Microsoft Purview DLP is a cloud-native, agentless solution designed to prevent data losses in your M365 environment. It incorporates machine learning capabilities to intelligently detect threats and automations to help mitigate data security incidents.

You also get granular policy controls to manage and protect sensitive information across apps, services, and devices – without adversely impacting employee productivity. Administrators can create, enforce, and fine-tune custom DLP policies to respond automatically when users request certain actions on sensitive data, thus minimizing the risk of data loss.

Microsoft Purview Privileged Access Management (PAM)

Microsoft Purview PAM enables organizations to better control and protect their privileged admin accounts and accounts with access to sensitive data or critical configuration settings. Its highly scoped and time-bounded approval workflow provides users with just-enough-access or just-in-time access to perform a task, thus preventing the exposure of sensitive data.

Microsoft Purview Information Protection

Microsoft Purview Information Protection (formerly Microsoft Information Protection) also provides an effective way to protect sensitive corporate data and avoid data losses. Harness its robust capabilities to:

• Identify and classify sensitive data across hybrid environments
• Assign sensitivity labels to data to facilitate prioritization of controls implementation
• Encrypt email messages and attachments to prevent unauthorized access
• Implement company-defined policies to protect data from unauthorized viewing or usage

Microsoft Purview Compliance Manager

Microsoft Purview Compliance Manager simplifies compliance by automatically managing several compliance-related tasks. These include:

• Inventorying and assessing the organization’s data protection risks
• Suggesting improvement actions and controls to facilitate compliance with relevant regulations and certifications
• Measuring progress in completing these actions to clarify the compliance posture
• Preparing reports for auditors

Compliance Manager calculates a compliance score depending on the data protection controls implemented to comply with certain regulations or policies. Use the score to identify compliance gaps and prioritize actions to fill those gaps.

Secure Score

Part of the Microsoft Defender portal, Secure Score provides points when you implement recommended security features to secure your identities, apps, and devices. Use these points to monitor your security posture and to identify the measures required to close the security gaps affecting your M365 assets.

Microsoft Entra ID

Microsoft Entra ID, formerly known as Azure Active Directory (Azure AD), is a popular cloud identity and access management solution to ensure secure access to all M365 apps and resources.

It includes all these robust capabilities to safeguard your organization:

• Multi-Factor Authentication (MFA): Eliminate the risk of passwords to better protect your apps and data
• Conditional Access: Apply strong conditional access controls to protect data inside applications and control how users/devices access corporate resources
• Identity Protection: Leverage advanced machine learning and high-assurance authentication methods to protect authorized identities
• Privileged identity management (PIM): Secure privileged accounts to mitigate the risk of compromise and breaches
• Single sign-on (SSO): Simplify app access for authorized users without compromising security

Data Encryption

Microsoft 365 follows a robust encryption process for many different kinds of content to prevent leakage and losses. Many strong encryption protocols are leveraged to encrypt both data at-rest and data in-transit. For example, BitLocker is used to encrypt files on a device, while Transport Layer Security (TLS) protocol is used to encrypt in-transit files and chats in Microsoft Teams. In contrast, in-transit emails are encrypted with Microsoft Purview Message Encryption.

Information Rights Management (IRM)

IRM is an effective way to set up and manage rights to Microsoft 365 assets. With IRM, admins can enforce policies governing the control and dissemination of confidential or proprietary information. Through these policies, they can prevent unauthorized people from performing certain activities on sensitive information in Microsoft 365 applications, such as printing, forwarding, or copying.

Mobile Device Management (MDM)

Your security team can take advantage of the built-in MDM for Microsoft 365 to:

• Remotely wipe devices to prevent the leakage of sensitive information
• Block unsupported devices from accessing Microsoft Exchange email
• Automatically reset devices to block access to potentially malicious users
• Strengthen security settings to protect corporate information from unauthorized or malicious access
• Limit email access and other services by setting up device security policies

Microsoft 365 Security Best Practices

The previous section highlights many of the security features built into Microsoft 365. However, Microsoft 365 security is not infallible. To prevent the compromise of your M365 environment, we advise you to implement all its native controls and also adopt the Office 365 security best practices highlighted below:

1. Take regular backups of critical data

Regular backups of your Microsoft 365 data can protect you from data losses. While Microsoft provides limited, short-term data loss recovery services, it’s advisable to also implement a third-party backup and DLP solution like SpinBackup.

SpinBackup prevents the unwanted removal of sensitive data and ensures its continued protection with:

• Automated daily backups
• Choice of 32 storage locations worldwide
• Backup to your preferred secure-cloud storage provider: GCP, Azure, AWS, or BYOS
• The freedom to enforce your own data protection policies

2. Enable MFA

Threat actors often aim to compromise Microsoft account credentials to attack organizations. Many of these credentials consist simply of user names and easily-guessable passwords, increasing the risk of theft and subsequent attack.

You can minimize the probability of password-based attacks by implementing MFA. MFA adds another verification method, such as one-time passwords or fingerprints, making it harder for adversaries to gain access to corporate assets. Even Microsoft has admitted in the past that MFA can block almost 100% of automated account takeover attacks.

3. Implement conditional access policies

Conditional access policies can help to protect your Microsoft 365 apps. With these policies, you can:

• Control access to applications based on certain conditions like user identities or locations
• Block unauthorized users from accessing sensitive resources
• Streamline security and access for remote teams
• Strengthen your identity security posture

4. Implement DLP policies

Detailed and clear DLP policies are vital to prevent unauthorized data access and data leaks. Aim to implement a policy that clearly states the types and locations of data that need to be protected, plus the levels of access assigned to each user and the procedures implemented to facilitate secure data access.

The policy should also identify, classify, and prioritize sensitive data, and detail the organization’s strategy to respond to adverse events and prevent data leaks. The most effective DLP policies also include rules for data archival and provide data audit trails to help with threat hunting and incident remediation.

5. Implement role-based access control (RBAC)

RBAC is a highly effective strategy to protect data from unauthorized access, modification, and deletion. The goal is to provide users with access rights and permissions based on the principle of least privilege so they can only access the data they need to perform their job. By limiting data access, RBAC helps protect business-critical information against misuse, leaks, and breaches.

6. Implement mobile data management and information rights management

With a robust MDM solution, you can ensure that connected devices are secure before they access corporate resources. You can do this by managing and enforcing security policies and restricting certain actions (e.g., copy/paste) on connected devices.

You can also safeguard enterprise data assets with IRM. Leverage an IRM solution to enforce access policies and to allow/deny specific activities. These protections will help keep information secure and safe from unauthorized users and malicious adversaries. Learn more about MDM here.

7. Implement advanced threat protection

New cyberthreats are being discovered almost every day. Often, these unknown threats are not detected by traditional security solutions, increasing the risk of a serious breach. You can protect your organization against these threats with advanced threat protection (ATP).

With an ATP solution, you can detect potential threats before they access critical or sensitive data. Equally important, you can mitigate threats quickly to minimize damage and accelerate recovery.

8. Implement anti-phishing and anti-malware solutions

Both anti-phishing and anti-malware solutions should be part of your security stack because they can help you:

• Identify and block threats before they pose a risk to the organization
• Implement proactive strategies to mitigate attacks
• Protect the loss of sensitive information
• Facilitate legal and regulatory compliance

9. Implement a backup solution for ransomware detection and response

​​Microsoft offers many security tools under the Microsoft 365 Defender umbrella to help organizations identify and remediate threats like ransomware. However, as with most built-in backup solutions provided by SaaS vendors, the solution also has an inherent flaw: it is not comprehensive and lacks robust features for ransomware protection. This is why businesses are advised to invest in third party backup and disaster recovery solutions for deeper and more robust data protection, particularly against ransomware threats.

Here’s a real-world example that shows how a third-party solution trumps Microsoft’s built-in protections.

In a head-to-head test, conducted in a controlled test environment, SpinOne identified and isolated 11 ransomware strains, generated alerts, isolated attacks, and even stopped the in-progress ransomware attacks. This result was significantly better than Microsoft Defender, a conventional security solution that struggled to detect several common strains under the same conditions.

As noted in a recent report by industry analyst firm DCIG, “Living in denial about either ransomware’s pervasiveness or a business’ reliance upon Microsoft 365’s continuous availability comes with significant risks, including downtime resulting in lost productivity and sales. This is why we recommend that organizations should consider advanced backup and security solutions like SpinOne not just as an additional layer of security but as a critical investment in their operational integrity and business continuity.”

Microsoft 365 Security FAQs

1. Does Microsoft 365 have security?

Microsoft 365 includes several built-in security measures to protect your apps and data.

2. Does Office 365 have built in antivirus?

Many O365 apps include antivirus capabilities to secure information and facilitate quick recovery from attacks.

3. What are the security benefits of Microsoft 365?

Microsoft 365 includes multiple security capabilities to protect your apps, workloads, and data from cyberattacks.

4. What are the 4 pillars of Microsoft 365 integrated security?

Four key pillars underpin the security philosophy of Microsoft 365: identity and access management, threat protection, information protection, and security management.

5. How do I secure my Office 365 account?

A multi-layered security approach is the best way to secure your Office 365 account.

Protect your M365 Data and Workloads with SpinOne

SpinOne is an all-in-one, fully-automated platform for reliable Microsoft 365 data protection. This solution incorporates the functionalities of SSPM, ransomware detection, DLP, and data backup and recovery so you can prevent, detect, and stop cybersecurity incidents that Microsoft doesn’t control. Want to take SpinOne for a spin? Click here to request a free demo.