How do browser extension scams hijack personal data?

Malicious browser extensions compromise personal data by operating within a privileged context inside the browser session, allowing them to access web pages, network requests, and stored data ^[1]. Cybercriminals often deploy these threats by acquiring legitimate, widely installed extensions and pushing silent malicious updates ^[2].

Mechanisms of Data Capture

• Keylogging and Form Grabbing: Malicious extensions record keystrokes and read sensitive inputs directly from login forms before information is transmitted to servers ^[3].
• Cookie and Session Theft: They extract active session cookies and authentication tokens from browser storage, which allows attackers to bypass multi-factor authentication and access accounts without passwords ^[4].
• Browsing History Exfiltration: Malicious add-ons monitor visited URLs, search queries, and behavioral profiles, sending this data to remote servers ^[5].
• Page and Traffic Manipulation: Some extensions inject content scripts into web pages to display fake login interfaces, alter network traffic, or redirect users to phishing sites ^[6].

Quick Tips for Choosing Safe Add-ons

• Minimize Extensions: Install only essential add-ons to reduce your overall security risk ^[7].
• Check Permissions: Review requested permissions carefully during installation and avoid add-ons asking for overly broad access, such as reading data on all websites when it is unnecessary for their function ^[8].
• Verify Developers: Stick to official web stores and research the developer's background, website, and update history before installing ^[9][10].
• Audit Regularly: Periodically review your installed extensions, remove unused tools, and clear your browser data if you suspect compromise ^[11][12].