Chrome extensions are ridiculously easy to trust. You find one that fixes a small annoyance, click Add to Chrome, approve whatever prompt appears, and probably never think about it again. I’ve done that so many times.
The problem is that some extensions have access to far more of your browser than their tiny toolbar icon suggests, and the extension you installed today might not remain exactly the same a year from now. Developers change, updates arrive, and occasionally something that started out perfectly legitimate goes bad. That makes it worth checking what your extensions are actually doing every once in a while.
It asks to “read and change all your data on all websites”
That is an awfully large keyring
This is Chrome’s own wording, not a dramatic interpretation of it. The warning appears when an extension requests particularly broad access to websites, which can allow it to read and modify content on pages across the sites you’ve permitted it to use.
That can be perfectly reasonable for an ad blocker or password manager that needs to work wherever you browse. I’d have many more questions if a calculator, basic new-tab extension, or helper built for one particular website wanted the same reach. Chrome’s own Web Store rules tell developers to request only the permissions they actually need, so an extension asking for considerably more access than its job seems to require deserves a closer look.
There’s a good reason to take that reach seriously. The 2019 DataSpii investigation identified eight browser extensions that collected browsing activity from more than four million users. The list included seemingly ordinary tools such as Hover Zoom and SpeakIt!, and researchers found exposed information ranging from private URLs and file attachments to corporate data and API keys.
Broad access alone isn’t proof that anything shady is happening, but it determines how much an extension could potentially see if it ever stops behaving as advertised. The bigger the gap between what the extension does and what it can access, the more interested I’d be in finding out why.
It suddenly asks for more permissions after an update
Funny, I don’t remember agreeing to that
I pay much more attention to extension permission prompts after installation than I used to. If an extension I’ve had for months suddenly gets disabled and Chrome asks me to approve additional access before it’ll run again, I want to know what changed before clicking anything.
Chrome does this when an update introduces certain new permissions that trigger a warning. The extension stays disabled until you approve them, which gives you a useful chance to ask whether the new request makes sense.
Sometimes it will. A developer may have added a feature that genuinely needs broader access. I’d be far less comfortable if a wallpaper extension suddenly wanted browsing-history access, or a simple utility built for one website started asking to interact with every page I visit.
Updates are also one of the points where a previously trustworthy extension can change direction. In December 2024, attackers phished an employee at security company Cyberhaven, gained access to its Chrome Web Store developer account, and published a malicious version of the company’s existing extension. That attack didn’t depend on users deliberately installing some obviously sketchy add-on. They already had the legitimate extension and received an update from a developer account they had every reason to trust.
Chrome can’t protect you from every bad update simply by showing another permission box, especially when malicious code abuses access an extension already had. Still, when Chrome does stop an update and ask you to approve something new, I wouldn’t waste the warning by clicking through it on autopilot.
The listed developer doesn’t match who built it
Same extension, new landlord
Chrome extensions can change ownership after they’re published, so the developer behind an extension today may not be the person you originally decided to trust. Whoever controls the project can also push future updates to people who already have it installed.
We’ve seen that go badly in very recent cases. As per Hacker News, security researchers documented QuickLens and ShotBird, two previously legitimate extensions that became malicious after ownership transfers. QuickLens changed ownership in February 2026, and researchers found that a later update stripped security protections from webpages and could load additional code remotely. ShotBird was caught in a similar ownership-transfer case.
Most people understandably don’t memorize the developer name attached to every extension they install. I certainly don’t. Still, if something I’ve had for years suddenly lists a company or developer I’ve never seen before, especially around the same time its behavior changes, I’d spend a minute looking into what happened.
An ownership change can be completely legitimate. Extensions get sold, abandoned projects get adopted, and developers hand things over all the time. The interesting part is when that change lines up with new permissions, strange network activity, ads, redirects, or other behavior the old version never had.
Chrome itself starts warning you about it
This is one warning I wouldn’t dismiss
You don’t need to follow extension-security news closely enough to recognize every compromised add-on by name. Chrome already performs some of that checking and can flag installed extensions that have been removed from the Chrome Web Store.
There are several possible reasons. A developer might have unpublished the extension, Google may have removed it for violating Web Store policy, or Chrome may have identified it as malware. Those situations obviously don’t carry the same level of risk, so the warning is where I’d start investigating rather than immediately assuming the worst.
The Great Suspender is a good example of the serious version. It had millions of users and had been one of Chrome’s most popular tab-suspension extensions. After the project changed hands and concerns emerged about code added under its new ownership, Google removed it from the Chrome Web Store in February 2021 and disabled it in users’ browsers after classifying it as containing malware.
For many users, Chrome disabling the extension was probably the first indication that anything had changed. That’s why I wouldn’t dismiss one of these warnings just because the extension worked perfectly yesterday. Check what Chrome is actually complaining about before deciding whether to turn it back on, replace it, or remove it completely.
The reviews pivot hard around one specific update
Sort by newest and watch the mood collapse
Lifetime ratings can hide a lot. An extension may have spent years collecting four- and five-star reviews before one bad update changes how it behaves, while the old average barely moves.
The RedDirection campaign uncovered in 2025 is a good example of how stale those trust signals can become. Koi Security’s initial investigation found 18 Chrome and Edge extensions with more than 2.3 million combined users. One was a color picker with a verified badge, more than 100,000 installations, and hundreds of reviews. Some of the extensions had behaved normally for years before later versions introduced malicious functionality.
We’ve seen plenty of other apparently legitimate Chrome extensions hide malicious behavior, which is why I care far more about what people are saying recently than the big rating sitting at the top of the listing. A sudden pile of complaints can come from an ordinary buggy release, of course, so the details are what I’d watch.
If several recent reviewers are independently mentioning redirects, unexpected ads, changed search results, new permission prompts, or pages becoming sluggish after the same update, I’d take that seriously. Sort by newest and see whether the complaints describe the same thing you’re experiencing.
A glowing review written three years and 20 versions ago may be describing an extension that has very little in common with the code running in your browser today.
Chrome’s Task Manager shows it working overtime
Why is the extension sweating?
Chrome has its own Task Manager, separate from the Windows one, and you can open it with Shift + Esc. It breaks down browser processes by resource usage and can show extensions alongside your tabs and other Chrome processes.
I wouldn’t panic just because an extension is using CPU, memory, or network resources. Password managers, notification extensions, blockers, cloud tools, and plenty of other add-ons have legitimate work to do in the background.
What catches my attention is activity that doesn’t fit the extension’s job. If something that’s supposed to wake up only when I click its toolbar icon keeps using network resources while I’m sitting on an unrelated webpage, I’d want to know what it’s talking to.
Task Manager won’t tell you exactly what data the extension is sending, and small bursts of traffic can be easy to miss. You’re also looking at resource usage rather than performing full network forensics. For a check that takes a few seconds and requires no extra software, though, it’s surprisingly useful for spotting an extension that seems much busier than its advertised purpose suggests.
It’s injecting things that have nothing to do with what it’s for
This extension has started freelancing
This is where things become much harder to shrug off. Extensions can display some advertising, and Chrome’s Web Store rules allow certain kinds of ads and affiliate behavior under specific conditions. What I’d be watching for is an extension altering pages or links in ways that have nothing to do with the feature I installed it for.
AllBlock gave us a wonderfully backward real-world example in 2021. Its advertised job was blocking ads, and it genuinely contained ad-blocking functionality. Imperva researchers also found code being injected into browser tabs that could modify links and route clicks through affiliate infrastructure.
So yes, an ad blocker ended up participating in the sort of unwanted monetization people install ad blockers to avoid.
I’d start asking questions if banner ads suddenly appear on sites that didn’t normally have them, searches begin passing through unfamiliar domains, links send me somewhere unexpected before reaching the destination, or websites suddenly start redirecting or opening by themselves.
Those symptoms can have other causes, which is why the easiest test is usually the simplest one. Disable the extension and repeat whatever you were doing. If the strange behavior disappears with it and comes back when you re-enable it, you’ve narrowed the problem down considerably.
A little suspicion goes a long way
Chrome extensions are easy to forget about because once they’re installed, most of them disappear into the browser and quietly keep whatever access you’ve given them. I’ve definitely treated plenty of them as set-and-forget software when I probably should’ve looked twice.
You don’t need specialist security tools to catch the obvious problems either. Most of the clues are already sitting somewhere in Chrome or showing up during normal browsing. One odd sign can have a perfectly reasonable explanation. When several start appearing around the same extension, that’s when I’d start reaching for the Remove button. If it does turn out to be malicious, there are a few cleanup steps worth taking after removing a bad Chrome extension rather than assuming uninstalling it ends the story.