Browser extensions offer enormous convenience: they block ads, manage passwords, boost productivity and customize the browsing experience. But every extension you install is third-party code running in your browser with potential access to all your online activity.
In 2025 and 2026, attacks through malicious extensions have increased by 40% according to Google data. Seemingly legitimate extensions have been compromised or sold to malicious actors, exposing the data of millions of users.
Only Install Extensions from Trusted Developers
Check reviews, the number of users, update frequency and the developer's reputation. Prioritize open source extensions whose code can be publicly audited. Be wary of extensions with few users but excessive permissions.
In the Chrome Web Store, verify the 'Privacy practices' section that Google has required since 2024. Extensions must declare what data they collect and for what purpose.
Scrutinize Permissions Carefully
The most dangerous permissions include: 'Read and modify all data on websites' (full content access), 'Access browsing history' (complete tracking of your activity), and access to camera, microphone or clipboard.
Chrome and Firefox have implemented more granular permission controls in 2025-2026. You can restrict an extension to specific sites instead of granting universal access. Take advantage of this feature.
Use Separate Profiles
Maintain different profiles for work and personal use. The work profile should contain only essential extensions with strict privacy standards. If a personal extension is compromised, your corporate information remains isolated.
Chromium-based browsers allow creating independent profiles with their own extensions, cookies and sessions. Firefox Multi-Account Containers offers a similar alternative.
Keep Extensions Updated and Remove Those You Don't Use
Outdated extensions are one of the most common attack vectors. Regularly review your installed extensions, remove those you no longer use and make sure the remaining ones are up to date.
A practical tip: schedule a monthly review of your extensions. If you can't remember why you installed it, you probably don't need it.
Monitor Browser Behavior
If you notice unexpected redirects, new ads that weren't there before, browser slowdowns or strange behavior in forms, an extension may be acting maliciously.
Disable extensions one by one to identify the problematic one. If the issue persists, run a full antivirus scan and consider reinstalling the browser.