Network security

Monitoring business communication tools like Slack for data infiltration risks

Christine McKenzie
October 7, 2020 by
Christine McKenzie


If you’re sending instant messages at work, chances are you’re using Slack, the business-oriented analog of WhatsApp or Discord. Slack currently boasts over 12 million users worldwide, and as more businesses turn to remote or hybrid work environments, that number is only expected to grow. But Slack’s popularity raises a very important question: exactly how secure is Slack? 

After all, most businesses have a trove of sensitive information that they would rather not see splashed across the dark web. But in the age of major hacks, your secrets are only as secure as your messaging platform. And, according to some cybersecurity experts, Slack has a few major vulnerabilities that every business should be aware of.

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Is Slack secure?

It’s a fair question to ask, since Slack is one of the most widely used instant messaging systems for business. It’s also a question that yields some surprising answers. 

Although Slack’s overall security has improved in the last couple of years, there are still some nagging issues yet to be resolved. Let’s take a look at some of Slack’s vulnerabilities.

Third-party apps

Third-party apps are the Achilles’ heel of the cybersecurity world. If a vulnerability arises in just one of the over 900 apps and bots that Slack users have to choose from, the issue can easily travel upstream to Slack. And since users at all levels have the power to install apps at will, this can be a difficult problem to manage. 

User vulnerabilities

Among Slack users, there are some common misconceptions about the platform’s privacy. Since the platform is invite-only, many users mistakenly think that everything they share via Slack will be private. 

Unfortunately, it’s not that simple. Since Slack members have the power to invite new members, edit user groups and invite guests into private channels, the system is not as private as many users perceive it to be. Users also have the ability to turn private files into external links which can then easily become publicly available URLs. In just a few clicks, anyone on the web with the URL can access the file. 

Is Slack encrypted?

Surprisingly, Slack does not have end-to-end encryption. This creates an enormous security risk for the mountains of sensitive data on Slack’s servers. Not only is this data vulnerable to outside hackers, but also malicious insiders who may wish to exploit it for personal gain. For that reason, it’s essential for businesses to seek out third-party security features to protect their users and data. 

Are there security solutions for Slack?

Despite its security flaws, Slack is still an enormously popular communication tool and doesn’t appear to be going anywhere fast. Luckily, security vendors have stepped in to fill some of the gaps in Slack’s defenses. And since Slack uses open-source APIs, vendors have access to all the tools they need to make safe, effective security solutions for the platform’s millions of users worldwide. 

To Slack’s credit, they’ve done a good job at making third-party security features accessible to users. Since they’re available in Slack’s app browser menu, installation is easy for users of all levels of tech proficiency. Once the feature is installed, the user will be protected from some of the major vulnerabilities native to Slack.

Among third-party security solutions for Slack, a few stand out as must-haves. SafeGuard Cyber is one of them. Their SaaS platform evaluates all incoming Slack communications, including messages, images, links and attachments, for malicious content. SafeGuard also offers compliance and archiving features. 

Another standout solution was created by Avanan, a vendor specializing in CASB solutions. Avanan’s Slack security platform includes URL filtering, hacked account detection and malware protection. The full administration dashboard also enables businesses to protect themselves from security threats like phishing links and compromised accounts. 

Conclusion: Third-party security integrations make it possible to monitor Slack for data infiltration risks

Slack does not natively enable message monitoring. And since most security threats arrive via message content in the form of infected links, attachments, and images, this is a huge security gap. 

However, third-party security features are available to bridge this gap. Platforms like Avanan and SafeGuard Cyber enable businesses to monitor Slack for data infiltration and cyberthreats, making the communication tool safe and secure for their ever-expanding user base. 



Slack's number of users from February 2014 to October 2019, by paid status (in 1,000s), Statista

Is Slack Secure? Slack Security Explained, Avanan

Are Slack messages really private? Here’s what to know, Mic

How Secure Is Slack for your Business?, Expert Insights

Learn Network Security Fundamentals

Learn Network Security Fundamentals

Build your skills with seven hands-on courses covering network models and protocols, wireless and mobile security, network security best practices and more.

Using Slack? Make Sure You Cover These 5 Security Risks, Password Boss

Christine McKenzie
Christine McKenzie

Christine McKenzie is a professional writer with a Master of Science in International Relations. She enjoys writing about career and professional development topics in the Information Security discipline. She has also produced academic research about the influence of disruptive Information and Communication Technologies on human rights in China. Previously, she was a university Career Advisor where she worked extensively with students in the Information Technology and Computer Programming fields.