Dangers of Browser Extensions, Security Threats, and Data Protection

The Danger of Browser Extensions

Browser extensions significantly expand the capabilities of Chrome, Firefox, Edge, and other browsers. However, along with convenience, they introduce real risks to information security, privacy, and the protection of personal data. Many users underestimate the threats associated with installing extensions, especially from unverified sources.

Excessive Permissions and Data Access

One of the main dangers of browser extensions is requesting excessive access permissions. Often, an extension’s functionality does not require full access to all websites and user data.

Nevertheless, by agreeing to such permissions, the user effectively grants the extension control over a significant portion of their browser activity. This means the extension can not only “see” visited pages, but also analyze their content, track user actions, and interact with data entered on websites.

What risks this creates

• Theft of logins and passwords.
• Reading entered data and forms.
• Tracking online activity.
• Access to cookies and session tokens.

Malicious and Compromised Updates

Even popular and previously safe extensions can become a threat over time.

Common scenarios

• Transfer of the extension to new owners.
• Injection of malicious code into updates.
• Automatic installation of updates without the user’s knowledge.

This is especially dangerous because trust in the extension has already been established.

Collection, Analysis, and Sale of User Data

Some extensions are monetized through the collection of user data. Such extensions may operate invisibly, gathering information about user activity in the browser and building a detailed behavioral profile. In most cases, data collection is not the primary function of the extension and is mentioned in the user agreement in fine print that most users do not read.

What data extensions may collect

• Browsing history.
• Search queries.
• IP address and geolocation.
• Behavioral data.

The collected information may be transferred to advertising networks or used for targeting.

Security Vulnerabilities in Extensions

Even if an extension is not malicious initially, errors in its code can be exploited by attackers. Vulnerabilities in extensions often allow execution of arbitrary JavaScript code, unauthorized access to user data, or interference with the operation of visited websites.

Possible consequences of vulnerabilities

• Execution of malicious code.
• Modification of web page content.
• Interception of user sessions.
• Use of the browser in botnets.

Outdated extensions without ongoing support pose a particular risk.

Fake and Counterfeit Extensions

Fake versions of popular extensions periodically appear in browser extension stores. This happens far more often than desired, and in practice, all responsibility falls on the user rather than on the extension marketplace.

Why fake extensions are dangerous

• They disguise themselves as well-known plugins.
• They use similar names and icons.
• They contain hidden malicious functionality.

Installing such an extension can lead to full browser compromise.

How to Protect Yourself from Dangerous Browser Extensions

1) Install only necessary extensions

Minimizing the number of extensions reduces security risks. Remove plugins that you do not use.

2) Analyze permissions before installation

If an extension requests access unrelated to its functionality, this is a reason to refuse installation.

3) Use trusted and popular extensions

Before installing, pay attention to:

• Number of active users.
• Developer reputation.
• Update frequency.
• Availability of an official website and privacy policy.

4) Regularly review installed extensions

Audit your browser extensions every few months and remove suspicious or outdated ones.

Conclusion

The dangers of browser extensions are often underestimated, but they can lead to data leaks, loss of privacy, and account compromise. A conscious approach to installing extensions, careful permission control, and regular audits can significantly improve security when using the internet (see also internet security basics and home PC protection).