Data Security in Microsoft 365 and Microsoft Teams

The beginning of a global pandemic was one of the biggest factors when it came to the rapid acceleration of digital transformation for many industries worldwide. In the context of widespread remote work, collaboration became one of the most important efficiency factors. In this context, solutions such as M365 and MS Teams became that much more widespread, offering plenty of different communication capabilities, simplifying data sharing, information exchange, and so on.

However, this kind of solution comes with its own share of security issues – especially when security teams have to figure out a way to ensure data governance without harming overall productivity. The topic of Microsoft 365 security is not that simple on its own, and the sheer number of different companies that use M365 or MS Teams in some capacity makes it more difficult to have a single data security strategy for every potential use case.

Seamless file sharing, for example, is a rather significant part of the popularity of Microsoft 365, with three main applications that can be used for it – OneDrive, SharePoint, and Microsoft Teams. File sharing with SharePoint and OneDrive is relatively easy and follows a similar pattern of the “Share” menu allowing for versatile data-sharing settings. The topic of secure file sharing in SharePoint, on the other hand, is not as simple or easy, since there are plenty of different potential issues that could lead to information being leaked in one way or another.

One of the biggest issues for data security in general, and for Microsoft 365 specifically, is a collection of factors under the name of “insider threats”. It includes a lot of different ways for a data breach to occur, such as employees falling for phishing attempts, malicious data exfiltration, unintentional data exfiltration, and even a simple error when typing the recipient’s email.

Luckily, there are also plenty of different strategies that a security team can take to try and counteract and/or mitigate these potential issues, including, but not exclusive to the Least Privileged Access strategy, relying more on MFA (Multi-Factor Authentication), or even restricting external sharing to specific accounts.

External sharing, or guest access, is another extremely useful feature that is both useful and a massive security risk. It makes the process of sharing information with external contributors that much easier, but it can also be a massive hole in the company’s security, which is why the first instinct for most security teams is to turn it off completely.

However, completely removing the ability to share files with external parties is extremely unproductive, since it is borderline necessary for most companies, and being able to control sharing rules is far better than having so-called unofficial sharing methods that would be more prone to data breaches. As such, guest access in MS Teams and other M365 applications should be controlled, not shut down completely – even though there may be a need for companies to use third-party solutions to achieve secure external data sharing.