Are Chrome Extensions Safe? Exploring the Risks

Browser extensions help simplify tasks, but are Chrome extensions safe? Most of these extensions request full access to all websites that you visit. Accepting the request allows the Chrome extensions to read and modify browser tabs, store collected data, or tamper with traffic. 

While some extensions request minimal permissions, others request extensive access. In this case, can Chrome extensions steal login info, such as your account passwords? Answering that, this guide walks you through Chrome extension security risks, how browser extension captures login data, and ways to protect against evil Chrome extensions. 

Are Browser Extensions a Security Risk?

Yes, browser extensions can be a security risk. Field Effect reports that in late 2024, researchers identified 30+ malicious Chrome extensions, installed by millions of users. These extensions secretly collected user data for a year and a half.

Browser extensions become a security risk when you grant excessive permissions. This mostly happens when you accept all permission requests without reviewing them. Moreover, their design, which is meant to add functionality, also creates inherent vulnerabilities. 

Key Factors of Chrome Extension Security Risks

It’s important to review the extension’s required permissions before accepting them. Here are the key factors that often result in Chrome extension security risks: 

• Excessive permissions: Extensions ask for specific permissions when you install them. Many users blindly accept these requests. It may result in the extension reading your browsing activities, history, or redirecting your searches. 
• Malicious intent from the start: Some extensions are created to be malicious. Developers can upload them to official browser stores. These extensions are useful tools and gain a user base through fake reviews. They are meant to steal your data, cryptocurrency, or hijack browsing sessions.
• Legitimate extensions turned malicious: This is a growing trend where legitimate, popular extensions with millions of users are sold to a new developer. The new owner might push a regular update with malicious code. Due to the previous trust, the new update deploys malware to users overnight. 
• Data harvesting: Various extensions work by collecting and selling user data for ads. They often have vague and overly broad privacy policies. Meaning, your browsing activities, personal information, and behavioural data are monetized without your knowledge. 
• Vulnerable extensions: Some well-intentioned extensions can contain security bugs or outdated code that hackers can exploit. They might use it to gain unauthorized access to the extension’s permission or use these extensions as a gateway. 

How Browser Extension Captures Login Data?

Browser extensions can capture your login data by injecting code, i.e., scripts, into webpages. This happens when you grant permissions, such as read and change site data. The extension then operates at a level between your keyboard and the website and between the site and your browser’s memory. This leads to data interception at multiple points.

Here’s a brief breakdown of how browser extensions can capture your login data: 

• Browser extensions monitor your browsing activities. The extension can see when you type your username and password into a login box. It can see every letter you type before the website even receives it. 
• The extension can read forms before submission: The browser extension can read and copy your login information from the login form when you click Log In. It sends the information to the hacker’s server while letting the normal login procedure continue to ensure zero suspicion. 
• It replicates the login interface: At times, hackers might create a fake, real-looking login box over the real one. All information goes to the hacker when you enter your credentials. 

Simply put, enabling all extension permissions without reviewing them is similar to giving a stranger permission to look over your shoulder every time you type a password on your computer. They just quietly write it down.

What Are the Chrome Extension Security Risks?

There were 111,933 Chrome Extensions available in 2024. And we believe the stats have only risen since then. However, granting extensive permissions may result in Chrome extension security risks. Here are the common browser extension risks: 

1. Monitor Browsing Activities

After installation, extensions can often access all of your activity across websites. This allows them to see everything you type. They can view everything from private messages and passwords to your search history and personal information.

2. Malicious Intent

Some extensions are designed by hackers to appear as useful tools, such as a PDF converter or a screen flashlight. However, these are created to secretly steal user data or bombard them with malicious advertisements.

3. Extensions Can Be Sold

A previously safe, popular extension can be sold to a new owner. That owner then updates it with hidden malicious code, instantly infecting all its users. You wake up one day, and your trusted extension is now spying on you.

4. Browser Extensions Can Be Hacked

Browser extensions can have security flaws that hackers can exploit to take control of them and use them for malicious activities, such as stealing your login information 

5. Extensions Run In the Background

Extensions operate continuously in the background once enabled. This background activity might degrade browser performance and consume system resources. Moreover, it might also enable behaviors such as cross-site tracking for user profiling, injecting unauthorized advertisements, or redirecting traffic to fraudulent websites.

Cases of Password-Stealing Chrome Extensions

Chrome extensions stealing passwords are growing common over time. As mentioned before, this is primarily due to users granting permissions without reviewing them. Here’s a list of the popular cases of Chrome extensions stealing passwords:

1. Cyberhaven and Allied Extensions Case (Late 2024)

Cybersecurity firm Cyberhaven identified a network of extensions. Most of these were posed as productivity and shopping extensions. The extensions were already installed more than 2.6 million times via the Chrome Web Store, making them look legitimate. They contained hidden malicious code that lay inactive for weeks before activating to steal sensitive data for up to 18 months. 

2. The Great Suspender (2021)

The Great Suspender was an extremely popular Chrome extension with millions of users that helped save computer memory (RAM). It would automatically “suspend” inactive browser tabs, freezing them to reduce resource usage, and reload them when clicked. It was considered an essential tool for power users with many tabs open.

The extension was sold in 2020 to an anonymous buyer. Shortly after the sale, a series of updates were pushed to users. The new version 7.1.8 and others contained obfuscated malicious code. It tracked users’ browsing history in detail, injected arbitrary code, and sent all this data to third-party servers. 

3. Fake ChatGPT Extensions

A wave of ChatGPT extensions flooded the Chrome Web Store in 2023-2024. These fake extensions used the immense popularity of ChatGPT to trick users into installing malware that stole sensitive data. 

These extensions used names, logos and descriptions almost similar to official OpenAI ChatGPT and promised useful features for quick AI access. Users granted excessive permissions and this resulted in credential harvesting, session hijacking and other attacks. 

How to Protect Against Evil Chrome Extensions?

Exercise caution before installing Chrome extensions, audit installed extensions, and use Chrome’s built-in security features to protect against Chrome extension security risks. Here are the practices we recommend to prevent credential theft from Chrome extensions: 

1. Be Selective Before Installing Extensions

Ask yourself whether you really need the extension you’re installing, since each extension is a potential risk. Verify the developer. Avoid extensions from unknown or suspicious developers. Check reviews and details, such as its reliability, rating, and recent reviews. Moreover, only install from the Chrome Web Store and not random links. 

2. Carefully Review the Permission Prompt

Read the permission prompt carefully. This is your most important defense against Chrome extension threats. Question everything, such as why does this specific extension need to read and change data on all websites? Prefer extensions with more limited permissions scoped like “on specific sites” before “all sites”. 

3. Regularly Audit

Conduct a monthly review of all installed extensions by navigating to chrome://extensions/. Any extension that is no longer actively utilized should be promptly uninstalled to minimize the application’s attack surface. Moreover, ensure that both the Chrome browser and all installed extensions are configured to update automatically.

4. Advanced Security Measures

We recommend using Chrome’s advanced security features, such as enabling safe browsing in Chrome’s settings for better threat detection. Use a dedicated browser profile with zero extensions for extremely sensitive activities. Additionally, use an antivirus to detect malicious browser activity or potential malware. 

Red Flag Checklist for Chrome Extensions

We recommend immediately uninstalling the Chrome extension if you notice any of these red flags: 

• Change in Ownership: The extension has undergone a transfer of ownership or a change in its listed developer entity.
• Expansion of Permissions: An update introduces a request for new permissions that appear unnecessary or disproportionate to the extension’s stated function.
• Negative Public Reporting: The extension is cited in credible cybersecurity news reports or advisories as being associated with malicious activity.
• Opaque Data Practices: The extension’s privacy policy is ambiguous, lacks specificity, or explicitly discloses the sale or sharing of user data with unspecified third parties.
• Delisting from Official Sources: The extension isn’t available on the official Chrome Web Store, suggesting it may have been removed by the platform administrator for policy violations or security concerns.

FAQs – Are Chrome Extensions Safe?

Final Note

Hackers can steal passwords through Chrome extensions when you install extensions and grant excessive permissions without reviewing them. We recommend installing only legitimate extensions, reading through their ratings and reviews, and carefully reading all requested permissions. 

For example, FastestPass offers dedicated browser extensions. Similarly, various other services offer legitimate extensions that you can trust. However, malicious extensions are often available via random links rather than a product’s website.