Browser extensions allow users to enhance the functionality of their web browsers. These extensions can range from password managers to ad blockers, and social media tools to productivity aids. Despite their convenience, many of these extensions can access sensitive information, making them an attractive target for cybercriminals.

A report from LayerX in 2025 revealed that while 99% of employees use browser extensions, more than half of these extensions (53%) are capable of accessing sensitive data such as passwords, cookies, and browsing history. This highlights how easily personal and organizational data can be compromised simply by using an extension that requests excessive permissions.

Moreover, while some browser extensions are designed to enhance the user experience, many are being used to collect private data without users’ consent. A study by Georgia Tech found that over 3,000 extensions automatically collect user data, including emails, medical records, and banking information, without providing clear disclosure to users. This raises serious concerns about user privacy, particularly with extensions that do not have transparent privacy policies.

The rise of malicious browser extensions is a growing cybersecurity threat. Cybercriminals have found ways to leverage these extensions to perform illicit activities, such as stealing sensitive data or hijacking browser sessions for financial gain.

In early 2025, GitLab reported that at least 16 malicious Chrome extensions had infected over 3.2 million users. These extensions, which were initially designed to improve user experience, were found to inject malicious code into browsers, allowing attackers to execute fraud schemes such as advertising and search engine optimization (SEO) manipulation. Iron Spear has been involved in the detection of malicious extensions, some of them quietly performing Bitcoin mining on behalf of a third party, using the host PC’s power and CPU without their knowledge. The reach of these malicious extensions demonstrates how easily users can be targeted without realizing it.

While browser extensions are an invaluable part of daily workflows, their risks cannot be ignored. It is essential for organizations to implement stringent security measures to safeguard their digital environment from potential threats posed by these extensions.

Organizations should regularly audit the browser extensions being used by their employees. This audit should focus on identifying extensions that have access to sensitive company data and assessing whether their permissions align with their intended function. Unnecessary extensions should be removed, and extensions with broad permissions should be reconsidered.

To reduce exposure, organizations should restrict the permissions granted to browser extensions. Extensions should only be allowed access to the necessary data and functionality required to perform their task. Limiting permissions helps mitigate the potential risk associated with extensions that may have broader access than needed.

One of the simplest and most effective ways to protect against browser extension risks is through education. Employees should be trained on the potential dangers of browser extensions, how to verify the safety of an extension before installation, and the importance of reviewing permissions. Organizations should also emphasize the risks of using extensions from untrusted or unknown sources.

Organizations can also implement enterprise-level control solutions that allow IT administrators to manage and monitor browser extensions. These solutions can restrict the installation of unauthorized extensions, enforce security policies, and ensure compliance with organizational security standards.

As browser extensions continue to play a key role in our digital lives, it’s vital to recognize the security risks they pose. From unauthorized data collection to malicious activity, these seemingly innocent tools can easily become a gateway for cybercriminals. By conducting audits, limiting permissions, educating employees, and implementing robust security measures, organizations can significantly reduce their exposure to threats stemming from browser extensions.

• LayerX, 2025. 99% of Employees Use Browser Extensions, and 53% Have Access to Sensitive Data. thehackernews.com
• Georgia Tech, 2024. Thousands of Browser Extensions Compromise User Data. gatech.edu
• GitLab, 2025. Malicious Chrome Extensions Affecting Millions of Users. gitlab-com.gitlab.io