If you’ve installed more than a handful of browser extensions over the years — a grammar checker, a coupon finder, an ad blocker, a “productivity” AI assistant — there’s a reasonable chance at least one of them has access to far more of your digital life than you intended to give it.
2026 has been a particularly bad year for this. Security researchers have caught hundreds of Chrome extensions, some with millions of combined installs, quietly exfiltrating browsing history, login credentials, and even the contents of conversations with ChatGPT and DeepSeek. Separately, an investigation alleged that LinkedIn itself was scanning visitors’ browsers for the presence of over 6,000 specific extensions and fingerprinting devices based on what it found. None of this requires anything resembling a sophisticated attack — it just requires a browser permission most people clicked “Allow” on without reading.
Why Extensions Are Such a Soft Target
A browser extension typically runs with broad permissions by design. To do its job — block ads, autofill passwords, check grammar — it often needs to read and modify the content of every page you visit. That’s not a bug; it’s how the extension model works.
The problem is that “read and modify every page” is also exactly the access needed to capture form inputs, scrape chat conversations, log browsing history, and exfiltrate any of it to a remote server, all without ever triggering an antivirus alert, because nothing about the behavior looks like traditional malware. The extension isn’t breaking into your system. You handed it the keys when you installed it.
This is made worse by how the Chrome Web Store and similar marketplaces operate. A legitimate extension with a good reputation and a large install base can be sold to a new owner, who then pushes an update that silently adds data-harvesting behavior — no new install required, no new permission prompt in many cases, just a routine update that most users never review.
What’s Actually Been Found in 2026
Extensions stealing AI chat conversations. Two Chrome extensions with a combined 900,000 installs were caught secretly collecting users’ ChatGPT and DeepSeek conversations along with general browsing data. For anyone who has used an AI chatbot to draft something personal, ask a medical question, or work through a financial decision, that’s a direct line from a private conversation to a third party that has no business seeing it.
Mass data exfiltration to data brokers. A security report identified 287 Chrome extensions — with a combined 37.4 million installations, roughly 1% of Chrome’s global user base — quietly sending browsing history to data brokers. At that scale, this isn’t a fringe problem affecting a handful of unlucky users; it’s a routine, large-scale data pipeline most of those users have no idea exists.
AI-branded extensions collecting more than they claim. An analysis of over 440 AI-branded Chrome extensions found that more than half collect user data beyond what’s disclosed or necessary for their stated function. The “AI” label has become a useful cover — people assume a new AI tool needs broad access to be smart, and extend more trust than they would to a plain utility.
Credential theft disguised as updates. In at least one documented case, a legitimate extension changed ownership, and the new owner pushed an update that replaced the normal interface with a fake “Chrome update” prompt designed to harvest saved passwords and credentials directly.
Large-scale ongoing campaigns. Separately, 108 malicious Chrome extensions were found stealing Google and Telegram account data from roughly 20,000 affected users — a reminder that this isn’t a one-time incident but an ongoing category of attack that keeps recurring with new extensions as old ones get caught and removed.
What This Means for Your Files and Photos
The direct risk is obvious — credentials, chat logs, browsing history. The less obvious risk is what extensions can see when you’re doing anything else in the browser: uploading a document to a cloud storage web app, viewing photos in a web-based gallery, filling out a form with personal information, or pasting something into a chat window.
An extension with page-content access doesn’t need to specifically target “cloud storage” to see what’s in it. If you’re viewing or uploading a personal file through a browser tab, and a malicious extension is running with content-script access in that same browser, it can potentially read whatever’s rendered on that page — including the contents of documents, form fields, and anything copied to the clipboard.
This is one of the practical arguments for keeping sensitive personal files — IDs, financial documents, photos you’d consider private — in a dedicated app rather than exclusively as browser-uploaded files sitting in web interfaces you access through a browser loaded with extensions of varying trustworthiness. A native app on iOS or Android doesn’t eliminate every risk, but it does remove the specific attack surface that browser extensions create.
How to Audit Your Own Extensions
This doesn’t require special tools — most of it is fifteen minutes spent somewhere you’ve probably never clicked.
Step 1: Open your extension list and actually look at it. In Chrome, go to chrome://extensions. In Firefox, about:addons. Most people install extensions over years and forget most of them exist. If you don’t immediately remember installing something, or don’t remember the last time you used it, that’s a candidate for removal regardless of whether it’s malicious.
Step 2: Check what permissions each one has. Click “Details” on each extension and look at its permissions. “Read and change all your data on all websites” is the broadest permission level and should be reserved for extensions you trust completely and use constantly — not a one-off tool you installed for a single task two years ago.
Step 3: Remove anything you don’t actively use. This is the single highest-impact step. An extension you haven’t used in six months provides zero value and full risk. Uninstall it.
Step 4: Check for ownership changes on anything you keep. Search the extension’s name along with “sold” or “ownership change” — this has become a recognizable pattern, and security researchers and tech press generally cover it when a popular extension changes hands and starts behaving differently.
Step 5: Be skeptical of new “AI” extensions specifically. Given how many AI-branded extensions were found collecting undisclosed data in 2026, treat a new AI tool’s permission request with at least as much scrutiny as you would any other extension — the AI label isn’t evidence of better data practices, and in the reports so far, the opposite has often been true.
Step 6: Use a password manager instead of letting the browser remember everything. If your saved credentials live in your browser’s built-in store, they’re sitting in the same environment as every extension you’ve installed. A dedicated password manager with its own access controls reduces what’s exposed if an extension does turn out to be compromised.
The “It Won’t Happen to Me” Problem
It’s worth being specific about why this category of risk gets underestimated, because the reasoning behind it is usually wrong in a predictable way.
Most people mentally model “getting hacked” as something that happens through a dramatic event — a phishing email, a suspicious download, a fake login page. A browser extension doesn’t look like any of those. It looks like a small, useful tool you installed deliberately, from an official store, that’s been sitting quietly in your toolbar for months or years without incident. The absence of an obvious red flag gets read as evidence of safety, when in most of the 2026 cases, the extension behaved normally for a long stretch before an update changed what it did, or it was harvesting data the whole time in a way invisible to the user.
This is also why install count and store presence are weaker signals of trustworthiness than they feel like. An extension with millions of installs and years of history sounds vetted. In practice, scale is exactly what makes an extension a more attractive acquisition target for whoever wants to buy it specifically to monetize its existing user base through data harvesting — the install count is the asset being acquired, not proof the asset is safe.
Where Extension Risk Connects to Account Security More Broadly
Stolen browsing history and chat logs are bad on their own, but the more serious downstream risk is what that data enables. An extension that captures login forms, autofill data, or session cookies can provide enough information to take over accounts directly, not just observe behavior from the outside.
This is part of why security guidance increasingly recommends layering protections rather than relying on any single safeguard. Two-factor authentication limits the damage if a password is compromised. A password manager limits how much an extension can scrape directly from autofill behavior. And keeping the most sensitive categories of personal content — financial documents, ID scans, private photos — outside of browser-dependent workflows entirely limits what’s exposed even if everything else fails.
None of these measures depends on correctly guessing which extensions are safe in advance, which matters because, as the 2026 cases show, that’s often impossible to know at install time even for careful, security-conscious users.
What a Reasonable Baseline Looks Like
You don’t need to run a bare browser with zero extensions to be reasonably protected — that’s not a realistic standard for most people. A more practical baseline:
Keep the number of installed extensions small and deliberate. Review permissions before installing, not after something goes wrong. Remove anything unused on a regular schedule — every few months is enough to catch most of the drift. And keep your most sensitive personal content — IDs, financial records, private photos — in places that don’t depend on browser extensions behaving well, because as 2026 has repeatedly shown, a meaningful number of them don’t.
daftei’s apps for iOS, Android, and web are designed so your most sensitive files don’t have to live exclusively inside a browser tab next to whatever extensions happen to be installed. Files are encrypted with AES-256 at rest and TLS 1.3 in transit, and daftei never sells data, never trains third-party AI on your content, and never shows ads — which also means there’s no incentive on daftei’s side to look anything like the data-harvesting extensions described above.