Office 365 Security Best Practices You Need to Implement Today

Cybersecurity is never far from the minds of most business professionals these days as the rate of cyber-attacks continues to climb. In fact, even the general public has accepted that they must maintain an increased understanding of cybersecurity basics to protect their data in today’s world. This clearly extends to the tools that they use at work, one of the most popular of which is the Office 365 suite of products. The fact is that this popular suite of business software is not immune to cyber-attacks, and it is important that you take steps to keep your company’s sensitive information safe. Keep reading to learn more about Office 365 security concerns and what you can do to keep your organization safe.

A Widely Used Product Can Still Have Security Concerns

In 2023, it was estimated that there are approximately 360 million active users of the Microsoft Office 365 suite of products. For reference, that is approximately the same number of people as the 5th largest country on the planet, Pakistan.

However, you shouldn’t allow the widespread popularity of this product to lull you into a false sense of security. Microsoft Office 365 products are not immune to security attacks. In fact, the program’s widespread nature is one of the things that attracts cybercriminals. They know that this is where a significant amount of important data is kept, and they will do everything within their power to get their hands on it. With that in mind, you need to know some of the best practices that you can use to keep yourself and your team safe while using these products.

Office 365 Security Best Practices

While Microsoft has gone to great lengths to enhance the security of its Office 365 products, each user must still protect themselves while using any technology product. That is why a list of best practices to help make that a reality is always going to be welcomed. We have some recommendations for you that have been tried and tested by others and have proven to be among the most effective ways to keep users safe when they use these products.

Start with Strong Passwords

We know that you have heard this advice before, but it bears repeating. You need to use strong passwords across the board to keep your data and profiles secure. These passwords are intended to be used to ensure that only the appropriate parties have access to the information contained within your Windows and Office 365 systems.

Make certain you use robust passwords with added layers of complexity so that they cannot be easily guessed if you want to maintain the highest levels of security over your information. You should also make sure that you do not reuse the same password across multiple websites and systems, as this will prevent all your accounts from becoming compromised if your password is breached. Using strong passwords isn’t just a recommendation; if your organization must maintain compliance with NIST 800-171, section 3.5.7 provides guidelines organizations must adhere to when creating new passwords including enforcing minimum password complexity and ensuring that new passwords are not on a list of weak or compromised passwords.

Create a Strong Password Policy

To protect your organization from a cyber-attack and ensure you are in compliance with NIST 800-171 and CMMC requirements, you need to create and enforce a strong password policy. The best password policy practices combine the right security settings with user education that informs staff of the importance of strong passwords and the guidelines they need to follow.

IT admins should enforce the following:

• Ban common passwords such as “abcdefg,” “123456” and “password.”
• Require an 8-character minimum password length.
• Enforce multi-factor authentication (see below).
• Supplement password policies with user education. It is particularly important that you educate users not to re-use company passwords anywhere else. The fact is that your employees are your first line of defense, and weak employee passwords increase the likelihood that data will be compromised.

Documenting and enforcing a strong password policy will be essential when it comes time for an audit, as your CMMC auditor is going to look for the following assessment objectives as they relate to the IA - Identification and Authorization domain:

• 3.5.7[a]: Password complexity requirements are defined.
• 3.5.7[b]: Password change of character requirements are defined.
• 3.5.7[c]: Minimum password complexity requirements as defined are enforced when new passwords are created.
• 3.5.7[d] Minimum password change of character requirements as defined are enforced when new passwords are created.

Multi-Factor Authentication

Proving that you are who you say you are is a big part of online security. Unfortunately, strong passwords alone aren’t enough to do this, as your password may become compromised. This is where multi-factor authentication (MFA) comes into play. Agile IT shows you how to deploy Azure MFA here.

Microsoft explains what this process is in the following way: “You may hear it called “Two-Step Verification” or “Multi-factor Authentication” but the good ones all operate off the same principle. When you sign into an account for the first time on a new device or app (like a web browser), you need more than just the username and password. You need a second verification method - what we call a second “factor” - to provx

Basically, this means that you are required to do something beyond just entering a username and password. That was the traditional way to get into your systems, but multi-factor authentication is considered more secure because it requires you to take a few extra steps to verify you are who you say you are.

The second factor of authentication may take the form of a code sent to the email address or phone number associated with your account to provide an extra layer of security. The necessity of multi-factor authentication is outlined in NIST 800-171 Identification and Authentication 3.5.3: Implement multi-factor authentication for access to privileged and non-privileged accounts. Your CMMC auditor is going to check for documentation showing that multi-factor authentication is being enforced and that the following assessment objectives are met:

• 3.5.3[a]: Privileged accounts are identified
• 3.5.3[b]: Multifactor authentication is implemented for local access to privileged accounts
• 3.5.3[c] Multifactor authentication is implemented for network access to privileged accounts
• 3.5.3[d]: Multifactor authentication is implemented for network access to non-privileged accounts

A best practice for deploying MFA would be to pair it with Conditional Access policies. This will give you more granular control over when and where MFA is required based on factors like location, device type, and the application being accessed. This gives you a more robust secure posture than if you required MFA across the board, as this allows for additional scenarios such as emergency access if all administrators get locked out of your network.

Work Together on Microsoft Teams

Understandably, you may be concerned about sending sensitive documents to people via their e-mail accounts. Instead of taking that kind of risk, you could use Microsoft Teams to collaborate with your team. This will make it possible for you to see those individuals face-to-face and know that you are truly talking to the right people. Plus, you’ll be avoiding the chance of accidentally sending sensitive info to the wrong person.

Additionally, Microsoft Teams, in combination with SharePoint, integrates well with Data Loss Prevention (DLP) policies to further protect sensitive information. By implementing DLP policies, your organization can prevent the accidental sharing of confidential data both within and outside of Teams. These policies can automatically detect sensitive content such as credit card numbers, Social Security numbers, or proprietary business information, and block or warn users before that data is shared. In SharePoint, DLP policies monitor and control document access, ensuring that only authorized personnel can view or download sensitive files. These safeguards ensure that even when collaborating in a dynamic environment, your data remains protected.

By using Teams and SharePoint with these security measures in place, you are not just improving collaboration, you are helping your organization reduce the risk of data breaches, improve compliance with regulatory standards, and maintain greater control over where sensitive information flows.

Monitor Activity Across the Platform

Staying constantly on the ball is the only way to maintain the high level of security necessary to bat down any potential threats as they arise. Constant monitoring will give you the best chances of preventing or catching a potential data breach, and it will help you maintain compliance with NIST 800-171 3.3.1: Create and retain system audit logs and records to the extent needed to enable the monitoring, analysis, investigation, and reporting of unlawful or unauthorized system access.

That is why we recommend looking at Microsoft Defender for Cloud Apps as a way to stay on top of the activity occurring throughout your Office 365 ecosystem. Implementing Microsoft Defender for Cloud Apps allows you to be alerted when there is any risky activity on the platform, addressing those issues more rapidly than you might have been able to otherwise. That is a big deal because you want to remove threats before they emerge and blossom into something larger scale.

Microsoft Defender for Cloud Apps can then be essential in helping boost your organization’s security in an era where more employees are using apps and company resources outside of the corporate perimeter, which can introduce new attack vectors. Fortunately, Microsoft Defender for Cloud Apps delivers full protection for SaaS applications, helping monitor and protect cloud app data. This software can then help not only protect your organization from a cyber-attack, but it can also help you prepare for an audit as CMMC auditors will look for the following objectives in the AU – Audit and Accountability domain:

• 3.3.1[a]: Audit logs needed (i.e., event types to be logged) to enable the monitoring, analysis, investigation, and reporting of unlawful or unauthorized system activity are specified.
• 3.3.1[b]: The content of audit records needed to support monitoring, analysis, investigation, and reporting of unlawful or unauthorized system activity is defined.
• 3.3.1[c]: Audit records are created (generated).
• 3.3.1[d] Audit records, once created, contain the defined content.
• 3.3.1[e]: Retention requirements for audit records are defined. 
• 3.3.1[f]: Audit records are retained as defined.

Establish a Data Loss Prevention (DLP) Policy

Your DLP policy should be used to ensure that sensitive information cannot be uploaded or emailed out to sources that don’t have a legitimate need to access that information. The specifics of the DLP policy that you set up for yourself will depend greatly upon the kind of business that you operate. However, you will want to include elements of protection such as being alerted if sensitive details such as bank account numbers, social security numbers, and the like are shared.

Spend time crafting your policy so you can keep everything safe throughout your organization. That is the only way that you can rest assured that you make some progress on keeping everything safe and secure.

This is particularly important if your organization handles controlled unclassified information (CUI), as NIST 800-171 requires organizations to control the flow of CUI within the system and between connected systems. In fact, your CMMC auditor is going to check that you have a documented and enforced DLP, as they are going to look for the following assessment objectives in the SC – Systems and Communications domain.

• 3.1.3[a]: Information flow control policies are defined
• 3.1.3[b]: Methods and enforcement mechanisms for controlling the flow of CUI are defined.
• 3.1.3[c]: Designated sources and destinations (e.g. networks, individuals, and devices) for CUI within the system and between interconnected systems are identified
• 3.1.3[d]: Authorizations for controlling the flow of CUI are defined.
• 3.1.3[e]: Approved authorizations for controlling the flow of CUI are enforced.

While Office 365 is one of the most widely used suites of business software, this doesn’t mean that it isn’t susceptible to cyber threats. Businesses must still stay vigilant and take precautions to secure their organization’s sensitive data, particularly if they handle CUI and they must maintain NIST 800-171 compliance.

Fortunately, you don’t have to deal with these security and compliance issues alone. By partnering with an MSP who has experience helping organizations achieve and maintain NIST compliance, you can rest easy knowing that your data is protected.

Agile IT has helped organizations comply with other related standards, such as NIST 800-171 and DFARS (Defense Federal Acquisition Regulation Supplement), which are foundational to CMMC. This experience ensures you will receive comprehensive guidance and support throughout the CMMC certification process.

We work to ensure you have a robust IT Service Management (ITSM) continuity plan in place, ability to anticipate future needs and align technological investments with your evolving business objectives while safeguarding against unexpected disruptions and ensuring rapid recovery. Contact us today to learn more about how we can help you succeed!