Evaluating the Safety of Browser Extensions: Are My Concerns Valid?

Your caution regarding browser extensions is entirely justified. Extensions, whether from Google's Chrome Web Store or Microsoft's Edge Add-ons store, can indeed pose security and privacy risks. Let's break this down so you can make an informed decision:

Why the Warning?​

The warning you see — "This app can read and change all your data on the websites you visit" — is a sober reminder of the level of access some extensions require. To function, extensions often need access to sensitive data such as:

• Your browsing history.
• The content of web pages you visit.
• The ability to modify page content.

This level of access can be innocuous (e.g., an ad blocker scanning for and blocking ads), but it can also be exploited.

Risks of Extensions​

1. Data Harvesting: Some extensions, especially from untrustworthy developers, collect your personal data, browsing habits, or even login credentials.
2. Malware Injection: Extensions can include malicious scripts to inject ads, redirect your browsing, or worse, install malware.
3. Abandoned Extensions: An extension may start out as safe but later be sold to a less scrupulous company, which then pushes updates with malicious intent.
4. Man-in-the-Browser Attacks: Extensions with extensive permissions can alter web pages for phishing or other fraudulent purposes.

Should You Be Concerned?​

Not needlessly, but yes, concern is warranted. However, you can take practical and effective steps to ensure your safety:

Extension Safety Checklist:​

1. Stick to Well-Known Developers
   Choose extensions from established developers, especially those with a strong reputation. Extensions like uBlock Origin for ad blocking are widely vetted by the community.
2. Check Permissions
   Evaluate the permissions requested by any extension before installing it. If it asks for far-reaching permissions unrelated to its core functionality, avoid it. For example, a weather extension should not need access to your browsing history.
3. Reviews and Ratings
   Read user reviews and check ratings on official stores like the Chrome Web Store or Microsoft Add-ons Store. Watch out for sudden drops in ratings — it could be a sign something changed (like a buyout or malicious update).
4. Update Regularly
   Keep your extensions up to date and check the changelogs when possible. If an extension shows suspicious updates, uninstall it.
5. Minimalist Approach
   Limit the number of extensions you install. More extensions equal more risk.
6. Use Browser Sandboxing and Anti-Malware Extensions
   Some browsers allow you to sandbox certain extensions, limiting their permissions (e.g., Edge allows you to run extensions in "enhanced security mode"). You can also install extensions like Malwarebytes Browser Guard to block malicious scripts and phishing attempts.
7. Audit Your Extensions
   Periodically review and remove any extensions you no longer use. This will minimize your exposure to security risks.

What About Ad Blockers?​

Ad blockers, like uBlock Origin and AdGuard, are generally safe if you stick to highly recommended options. That said, always monitor their permissions and whether they get sold to a new owner (yes, this has happened before!.

TL;DR:​

You’re not being paranoid — your concerns are well-founded, considering the broad access many extensions require. Stick to reputable extensions, review permissions carefully, and maintain a minimalist collection. For the average user, this approach is sufficient to stay safe while enjoying the benefits of browser add-ons.
If you’re debating specific extensions, let me know! I can help analyze their reputations or permissions.