Microsoft Office 365 Security Challenges and Solutions

Microsoft Office 365 is one of the most popular cloud suites for businesses worldwide, with more than 250 million monthly active users. With the rise in remote work, its popularity has grown even more as it enables rapid collaboration between employees. But with virtual collaboration, there comes increased security risks and failures such as accidental sharing of confidential data and data leakage. Microsoft claims to provide the best security solutions for Office 365 users to prevent them from cyber threats. This may be true, but there are still security challenges that companies need to address. 

Unauthorized Access 

Many companies work on a general principle that employees should have access to Microsoft Office applications, but having unrestricted access creates cyber security risk. Granting employees more access than they need can also unintentionally give hackers access to a lot of sensitive data. A hacker isn’t the only threat though… since Office 365 is hosted on the cloud and is accessible from anywhere, ex-employees can still access applications if their privileges aren’t removed.   


  • Assign role-based access for all applications. Businesses that do this keep their sensitive data protected because it ensures that employees can only access information needed to perform their jobs.
  • Microsoft recommends having at least two but no more than four global admins for your business. This will provide backups if passwords are lost because only a global admin can reset another global admin’s password.

Credential Attacks 

If a cyber criminal gets ahold of Microsoft Office 365 login credentials, this can create an opportunity for a severe data breach. Because Office 365 is so widely used, it’s a preferred target for cyber criminals—in fact, Microsoft Office is at the top of the list for credential phishing attacks. Once attackers get login credentials, they can access a user’s Microsoft 365 mailbox, SharePoint folders, and OneDrive files. 


  • Always use a multi-factor authentication method for your Office 365 suite, which adds extra layers of security to your account. Users have to prove they are who they claim to be. 
  • Create a password policy that provides guidelines for employees’ passwords. 
  • Secure passwords before they reach the network by encrypting them with a password manager.

Leakage and Data Loss 

Microsoft Office 365 and similar cloud solutions provide businesses with large data storage capacity and an easy way to access the data. Microsoft Office applications like OneDrive, SharePoint, Teams, and Outlook provide users a simple way to send information to one another. However, the ease of accessing data sometimes leads to intentional or unintentional data leakage, which could be detrimental to a business. Data loss occurs for several reasons, including user errors or cyberattacks through your network or even a third-party system, leaving businesses vulnerable if immediate actions are not taken. 


  • Evaluate the security of your vendors and cut ties with vendors who don’t meet your security standards.   
  • Monitor your network access. Cyber criminals do their research before attacking, so watching for suspicious activity before attacks occur is key to protecting your data
  • Classify and back up sensitive data allowing only role-based permissions access.

Email Security 

The first point of entry for many attacks is through a company’s email system. Spam and malicious emails containing malware start attacking a company’s network when a user opens an attachment or clicks on a link in the email. All it takes is one click from an employee to wreak havoc throughout an entire organization’s network. Microsoft 365 includes built-in safeguards against malware, but having multiple points of protection increases overall security.


  • Train your employees to recognize harmful emails.
  • Block attachments that use file types common for malware.
  • For sensitive emails, make sure they are encrypted. This ensures that email content is viewed only by those intended to receive it.

File-Sharing Security 

Microsoft products are built for productivity and collaboration. File sharing is necessary for collaboration, but it’s also a business risk and should be treated that way. Microsoft products that enable file sharing include SharePoint, OneDrive, Microsoft Teams, and Microsoft 365 Groups. Some of these products allow for external file sharing, but all are used for internal sharing. Varonis claims that 60% of shared business files are only shared internally. So even though files can be shared externally, the top security concern for Microsoft 365 is most likely an internal one. Sharing the wrong files with the wrong people or even sharing the right files with the right people can lead to security problems. 


  • Keep a record of documents and audit them to see who is accessing them and how often. If documents are not accessed for a certain amount of time, they should be archived and removed from the network
  • Establish best business practices for file sharing, including password protection, expiring links, varied permissions, virus scanning, physical protection, encryption, and system monitoring.
  • Use file encryption when sharing sensitive files. 

Even with security measures built into Microsoft 365, there are additional steps businesses can take to reduce cyber security risks. There are several safeguards that can be initiated to cover multiple risks, and this is where companies should start to get the most security for network coverage. A Managed Services Provider can assist with evaluating your needs and required coverage. 

Visual Edge specializes in managed IT services and security, cloud computing, and print/copy solutions for businesses across the U.S., including remote offices. The company has more than 30 years of technology service with a national network of expert engineers. Request your no-obligation assessment today and get a free dark web analysis.