Beyond Chrome: Risks of Malicious Extensions Across Traditional and AI Browsers

Browser extensions have evolved over the years into powerful productivity platforms to streamline workflows, integrate business tools, and optimize how work is done. Now in the age of AI, extensions are once again evolving to enable advanced automation and data-driven decision-making directly in the browser. And as these extensions continue to mature, so will the cyberattacks.

Today's extension-based attacks do not discriminate; they target every traditional browser, including Chrome, Edge, Firefox, and more, as well as the new AI-powered browsers like ChatGPT's Atlas and Perplexity's Comet. They adapt to each environment's security nuances. Most enterprises assume that if they secure one browser, it's enough.

The reality is that cross-platform extension threats are becoming increasingly common, and organizations must take broader vigilance. In this article, you'll learn why leveraging a Secure Enterprise Browsing (SEB) platform is critical for organizations to keep up with today's malicious extension threats.

Extensions Are Here to Stay

Browser extensions have given way to billion-dollar companies and deliver real value to enterprises and their employees. They often enhance and speed up workflows, improve writing clarity, and reduce repetitive actions.

For example, the grammar and writing helper Grammarly can save countless editing hours for writers by making fast corrections. Research assistants such as Scripsy AI or TLDR extensions help users summarize pages and validate sources. Finally, automation helpers like Text Blaze reduce the time spent on manual data entry.

Enterprises must allow employees to adopt extensions or risk falling behind. So, the safe and secure enablement of these extensions must be top of mind for CISOs worldwide.

Why Organizations Can't Rely on a 'Single-Browser' Security Posture

Enterprises must look past a single-browser security posture because of today's highly distributed and connected workforce. Users frequently switch between different browsers according to specific workflows, and this significantly broadens the attack surface. Using multiple browsers (either by the same user or others), allows attackers to traverse platforms more easily. Making this challenge even more difficult, security policies and detection capabilities are often inconsistent across platforms.

How Extension Risks Vary Across Browsers

Chrome

Google Chrome pioneered Web Extensions and continues to be the world's most popular web browser, making its Chrome Web Store the prime target for threat actors seeking to pull off attacks at scale. Chrome's permission model is robust but does still allow for some risky access that can be abused. Chrome does have an automated and manual review process to detect malicious extensions, however, some threats do get approved through code obfuscation and delayed attack activation.

AI Browsers

Extensions in AI browsers like ChatGPT's Atlas and Perplexity's Comet, have elevated permissions to read and modify web data, interact with APIs, and control browser behaviors. One unique AI-specific vulnerability is a prompt injection attack, where attackers trick the browser's AI agent with harmful commands. Unencrypted data transmissions, automated collections sent to external services, and the complexity and interconnectedness of AI browsers mean many users inside a network can be impacted at once before defenses catch up.

Edge

Microsoft Edge is built on Chromium, so it supports almost all Chrome extensions directly. However, users can download and install extensions from both the Chrome Web Store and the Microsoft Add-ons Store. While Edge maintains Chrome's permissions approach, this dual web store approach does increase the risk surface.

Firefox

Firefox has an open extension ecosystem powered by its own WebExtensions API. It maintains compatibility with many Chrome extension models; however, it does not enforce the full Manifest V3 transition that Google unveiled in 2018. As a result, people who are less aware might be confused or more easily tricked if they are just used to looking at Chrome extensions.

Safari

Extensions on Apple's Safari browser must be packaged within the Apple ecosystem and distributed on the Apple App Store. This enforces stricter review processes and can isolate permissions. Apple's architecture enables Safari to manage access granted to each extension tightly. Third-party code must also meet Apple's security and privacy criteria before the release of any updates.

Brave

Brave also uses a Chromium extension model, making most Chrome extensions available on its browser. Brave, however, does add privacy-focused restrictions as its architecture blocks certain trackers and enforces specific privacy settings. This privacy focus can limit the effectiveness of extensions relying on third-party integrations.

Emerging AI-Powered Trends

Web extensions continue to evolve both in technological prowess and security risk. Increasingly sophisticated attacks are being conducted through AI-powered extensions and are used to compromise all sorts of highly sensitive data.

• AI clones: Cybercriminals are increasingly branding malicious extensions as useful AI tools, masking malicious code or data siphoning under popular service labels.
• Borderless campaigns: Attackers increasingly design payloads to operate across multiple browsers to expand persistence.
• Platform evasion: Many malicious extensions include platform-detection code, activating only on specific browsers to remain undetected.
• Dedicated Enterprise Browsers: Attackers are now testing enterprise-specific distribution channels to target admins who control extension deployments at scale.

Defensive Strategies

The most effective defensive strategy against multi-platform malicious extension campaigns is comprised of a combination of Secure Enterprise Browser technology and continuing user education.

Rather than relying on individual browser controls, organizations should adopt platform-agnostic solutions that make extension management easy. These solutions should facilitate continuous auditing of installed extensions across every browser used within an organization. Doing so climates the blind spots created by browser-specific oversight.

Equally important is the need for user education. Annual training exercises for employees to better familiarize themselves with extension-related risks are paramount. Employees should also be trained in indicators of compromise across any browser or device they might use for work.

By utilizing browser-agnostic security platforms, CISOs can achieve comprehensive, scalable defense without forcing workflow disruptions or harming productivity.

Final Thoughts

Malicious extensions are not bound by a single platform. AI is also lowering the bar for attackers to produce convincing, malicious extensions and to social-engineer users into installing them. AI Browser features and extension permissions can be abused to inject deceptive interfaces, exfiltrate tokens, or perform harmful actions while appearing legitimate. That means the productivity upside must be balanced with stronger review, tighter permissions, and user education.

Extension security continues to evolve, but differences in browser architecture and the extension review processes ultimately shape how each browser detects and mitigates malicious extension risk. To keep pace with attackers' cross-browser methods, organizations must pursue a holistic, Secure Enterprise Browser (SEB) platform. Security teams must treat all extension ecosystems as potential entry points for bad actors.

To speak with a browser security expert or learn more about browser-agnostic Secure Enterprise Browser (SEB) solutions, click here.

About the Author: Hananel Livneh is a Senior Director of Product Marketing at Seraphic. Hananel was most recently a PMM at CrowdStrike. Prior to that, he served as the Head of Product Marketing at Adaptive Shield, a SaaS security company, and as a Senior Product Analyst at Vdoo, an embedded cybersecurity company. Hananel holds an MBA with honors from the OUI, and has a BA from Hebrew University in Economics, Political Science, and Philosophy (PPE).