Staying Safe with Chrome Extensions

Posted by Benjamin Ackerman, Anunoy Ghosh and David Warren, Chrome Security Team

Chrome extensions can boost your browsing, empowering you to do anything from customizing the look of sites to providing personalized advice when you’re planning a vacation. But as with any software, extensions can also introduce risk.

That’s why we have a team whose only job is to focus on keeping you safe as you install and take advantage of Chrome extensions. Our team:

• Provides you with a personalized summary of the extensions you’ve installed
• Reviews extensions before they’re published on the Chrome Web Store
• Continuously monitors extensions after they’re published

A summary of your extensions

The top of the extensions page (chrome://extensions) warns you of any extensions you have installed that might pose a security risk. (If you don’t see a warning panel, you probably don’t have any extensions you need to worry about.) The panel includes:

• Extensions suspected of including malware
• Extensions that violate Chrome Web Store policies
• Extensions that have been unpublished by a developer, which might indicate that an extension is no longer supported
• Extensions that aren’t from the Chrome Web Store
• Extensions that haven’t published what they do with data they collect and other privacy practices

You’ll get notified when Chrome’s Safety Check has recommendations for you or you can check on your own by running Safety Check. Just type “run safety check” in Chrome’s address bar and select the corresponding shortcut: “Go to Chrome safety check.”

User flow of removing extensions highlighted by Safety Check.

Besides the Safety Check, you can visit the extensions page directly in a number of ways:

• Navigate to chrome://extensions
• Click the puzzle icon and choose “Manage extensions”
• Click the More choices menu and choose menu > Extensions > Manage Extensions

Reviewing extensions before they’re published

Before an extension is even accessible to install from the Chrome Web Store, we have two levels of verification to ensure an extension is safe:

1. An automated review: Each extension gets examined by our machine-learning systems to spot possible violations or suspicious behavior.
2. A human review: Next, a team member examines the images, descriptions, and public policies of each extension. Depending on the results of both the automated and manual review, we may perform an even deeper and more thorough review of the code.

This review process weeds out the overwhelming majority of bad extensions before they even get published. In 2024, less than 1% of all installs from the Chrome Web Store were found to include malware. We’re proud of this record and yet some bad extensions still get through, which is why we also monitor published extensions.

Monitoring published extensions

The same Chrome team that reviews extensions before they get published also reviews extensions that are already on the Chrome Web Store. And just like the pre-check, this monitoring includes both human and machine reviews. We also work closely with trusted security researchers outside of Google, and even pay researchers who report possible threats to Chrome users through our Developer Data Protection Rewards Program.

What about extensions that get updated over time, or are programmed to execute malicious code at a later date? Our systems monitor for that as well, by periodically reviewing what extensions are actually doing and comparing that to the stated objectives defined by each extension in the Chrome Web Store.

If the team finds that an extension poses a severe risk to Chrome users, it’s immediately remove from the Chrome Web Store and the extension gets disabled on all browsers that have it installed.

The extensions page highlights when you have a potentially unsafe extension downloaded