Ads promoted browser extensions as tools to find manuals, convert PDFs, or make searches safer. But many of these extensions sent users’ search queries through servers controlled by their operators.

Socket researcher John Tuckner identified 319 extensions with an estimated 13.4 million installs over a decade. The extensions hijacked users’ default search settings and routed their searches through servers controlled by the operators before sending them to Yahoo or Bing. This gave the operators access to users’ queries and let them earn referral payments.

Socket says the extensions were promoted through ads on networks including Google Ads, promoting tools such as “manual finders,” “PDF converters,” “safe search,” and “AI search.”

The extensions were listed in Google’s official store, but most were unlisted. That means people with a direct link could visit a listing and install an extension, while ordinary searches in the store would not show it. An ad offered help with an immediate task, a landing page encouraged installation, and the official store provided a familiar place to complete it.

Search hijacking

The main risk was that operators could see what users searched for. Searches can reveal health worries, financial problems, workplace interests, or other personal matters. Socket says queries were often associated with a unique identifier, which could let the operators link a user’s searches over time.

The proxy could also choose where to send a search. Socket says this could potentially direct users to phishing or malware pages, but it did not find evidence that the extensions had done so.

What should users do?

If your searches start going astray, or you installed a search, PDF-converter, manual-finder, or security extension after clicking an ad, check what’s installed.

• Review your extensions. Enter chrome://extensions in Chrome’s address bar. Remove extensions you don’t recognize, no longer use, or don’t trust. To remove one, select Remove and confirm. If you’re unsure about an extension, check it against the list at the end of Socket’s blog.
• Check your search settings. In Chrome, at the top right, select More (the three-dot menu), then Settings > Search engine. If Chrome says an extension is controlling a setting, review or remove that extension. The absence of this notice doesn’t confirm that all your extensions are safe.
• Run a Malwarebytes scan to check for malicious extensions and other malware that could be affecting your device.

From reporting threats to removing them.

Cybersecurity risks should never spread beyond a headline. Keep threats off your devices by downloading Malwarebytes today.

Socket’s threat researchers found three malicious Firefox extensions that impersonated the Phantom, Jupiter, and Bitget crypto wallets.

Once installed, the malicious extensions stole recovery phrases and private keys, which would provide the attacker with full control of a wallet.

A crypto wallet is an app, browser extension, or physical device that lets you manage cryptocurrency such as Bitcoin. Despite its name, it doesn’t actually hold your coins. Those are recorded on a blockchain, a shared digital record of transactions. Instead, the wallet manages the secret digital keys that let you access and spend them.

When you create a wallet, you may be given a recovery phrase: a list of words you can use to restore access. Write it down and store it offline. It’s a backup of your keys, not just an ordinary password. Anyone who gets hold of it can take control of your funds, which is why fake wallet extensions try to steal it.

Cybercriminals listed three fake wallet extensions on Firefox Add-ons, impersonating Phantom, Jupiter, and Bitget. The genuine wallets offer extensions for other browsers: Jupiter lists Chrome, Brave, and Edge; Bitget’s extension is for Chrome; and Phantom says its Firefox extension is no longer supported.

The malicious extensions looked for 12-, 15-, 18-, and 24-word recovery phrases, as well as Ethereum and Solana private keys. They could read input fields, detect pasted text, and scan screens displaying recovery phrases.

A recovery phrase or private key is a bearer secret: whoever holds it controls the wallet and can move its assets. The Phantom variant’s backend logged captured secrets, sent them to a Telegram bot, and automatically moved funds to hardcoded payout addresses. Those addresses covered Ethereum, BSC, Polygon, Arbitrum, Optimism, Base, Avalanche, Solana, and Bitcoin. The Phantom variant could read a phrase both when it was typed during import and when it was displayed on a reveal screen.

How to stay safe

Socket says all three listings were live on Firefox Add-ons during its analysis and have since been removed. But if you find one of these extensions in your Firefox browser, you should:

• Remove the extension. Use the three-dot menu next to it and choose Remove.
• If you ever entered a phrase or key, create a new wallet on a clean device and move your assets immediately. Treat the old wallet as compromised.
• In the future, install wallets only from the vendor’s official website link, not from store search results.
• The fake Phantom listing asked to access data on all websites and had no privacy policy. These are warning signs to look out for.
• Use an up-to-date, real-time anti-malware solution that blocks malicious websites.

Never enter your recovery phrase on a website. Enter it only in the official wallet app when restoring. Wallet support will never ask for it.

IOCs

The malicious extensions:

• Phantom impersonator: add-on ID 3092199
• Jupiter impersonator: add-on ID 3092666
• Bitget impersonator: add-on ID 3092059

Subdomains:

• bonto[.]io
• phantom[.]bonto[.]io
• jupiter[.]bonto[.]io
• bitget[.]bonto[.]io
• coinbase[.]bonto[.]io
• exodus[.]bonto[.]io

IP addresses:

• 104.21.34[.]69
• 172.67.155[.]198

From reporting threats to removing them.

Cybersecurity risks should never spread beyond a headline. Keep threats off your devices by downloading Malwarebytes today.

Researchers have found yet another family of malicious extensions in the Chrome Web Store. This time, 30 different Chrome extensions were found stealing credentials from more than 260,000 users.

The extensions rendered a full-screen iframe pointing to a remote domain. This iframe overlaid the current webpage and visually appeared as the extension’s interface. Because this functionality was hosted remotely, it was not included in the review that allowed the extensions into the Web Store.

In other recent findings, we reported about extensions spying on ChatGPT chats, sleeper extensions that monitored browser activity, and a fake extension that deliberately caused a browser crash.

To spread the risk of detections and take-downs, the attackers used a technique known as “extension spraying.” This means they used different names and unique identifiers for basically the same extension.

What often happens is that researchers provide a list of extension names and IDs, and it’s up to users to figure out whether they have one of these extensions installed.

Searching by name is easy when you open your “Manage extensions” tab, but unfortunately extension names are not unique. You could, for example, have the legitimate extension installed that a criminal tried to impersonate.

Searching by unique identifier

For Chrome and Edge, a browser extension ID is a unique 32‑character string of lowercase letters that stays the same even if the extension is renamed or reshipped.

When we’re looking at the extensions from a removal angle, there are two kinds: those installed by the user, and those force‑installed by other means (network admin, malware, Group Policy Object (GPO), etc.).

We will only look at the first type in this guide—the ones users installed themselves from the Web Store. The guide below is aimed at Chrome, but it’s almost the same for Edge.

How to find installed extensions

You can review the installed Chrome extensions like this:

• In the address bar type chrome://extensions/.
• This will open the Extensions tab and show you the installed extensions by name.
• Now toggle Developer mode to on and you will also see their unique ID.

Removal method in the browser

Use the Remove button to get rid of any unwanted entries.

If it disappears and stays gone after restart, you’re done. If there is no Remove button or Chrome says it’s “Installed by your administrator,” or the extension reappears after a restart, there’s a policy, registry entry, or malware forcing it.

Alternative

Alternatively, you can also search the Extensions folder. On Windows systems this folder lives here: C:\Users\<your‑username>\AppData\Local\Google\Chrome\User Data\Default\Extensions.

Please note that the AppData folder is hidden by default. To unhide files and folders in Windows, open Explorer, click the View tab (or menu), and check the Hidden items box. For more advanced options, choose Options > Change folder and search options > View tab, then select Show hidden files, folders, and drives.

You can organize the list alphabetically by clicking on the Name column header once or twice. This makes it easier to find extensions if you have a lot of them installed.

Deleting the extension folder here has one downside. It leaves an orphaned entry in your browser. When you start Chrome again after doing this, the extension will no longer load because its files are gone. But it will still show up in the Extensions tab, only without the appropriate icon.

So, our advice is to remove extensions in the browser when possible.

Malicious extensions

Below is the list of credential-stealing extensions using the iframe method, as provided by the researchers.

We don’t just report on threats—we remove them

Cybersecurity risks should never spread beyond a headline. Keep threats off your devices by downloading Malwarebytes today.

Cybercriminals behind a campaign dubbed DEAD#VAX are taking phishing one step further by delivering malware inside virtual hard disks that pretend to be ordinary PDF documents. Open the wrong “invoice” or “purchase order” and you won’t see a document at all. Instead, Windows mounts a virtual drive that quietly installs AsyncRAT, a backdoor Trojan that allows attackers to remotely monitor and control your computer.

It’s a remote access tool, which means attackers gain remote hands‑on‑keyboard control, while traditional file‑based defenses see almost nothing suspicious on disk.

From a high-level view, the infection chain is long, but every step looks just legitimate enough on its own to slip past casual checks.

Victims receive phishing emails that look like routine business messages, often referencing purchase orders or invoices and sometimes impersonating real companies. The email doesn’t attach a document directly. Instead, it links to a file hosted on IPFS (InterPlanetary File System), a decentralized storage network increasingly abused in phishing campaigns because content is harder to take down and can be accessed through normal web gateways.

The linked file is named as a PDF and has the PDF icon, but is actually a virtual hard disk (VHD) file. When the user double‑clicks it, Windows mounts it as a new drive (for example, drive E:) instead of opening a document viewer. Mounting VHDs is perfectly legitimate Windows behavior, which makes this step less likely to ring alarm bells.

Inside the mounted drive is what appears to be the expected document, but it’s actually a Windows Script File (WSF). When the user opens it, Windows executes the code in the file instead of displaying a PDF.

After some checks to avoid analysis and detection, the script injects the payload—AsyncRAT shellcode—into trusted, Microsoft‑signed processes such as RuntimeBroker.exe, OneDrive.exe, taskhostw.exe, or sihost.exe. The malware never writes an actual executable file to disk. It lives and runs entirely in memory inside these legitimate processes, making detection and eventually at a later stage, forensics much harder. It also avoids sudden spikes in activity or memory usage that could draw attention.

For an individual user, falling for this phishing email can result in:

• Theft of saved and typed passwords, including for email, banking, and social media.
• Exposure of confidential documents, photos, or other sensitive files taken straight from the system.
• Surveillance via periodic screenshots or, where configured, webcam capture.
• Use of the machine as a foothold to attack other devices on the same home or office network.

How to stay safe

Because detection can be hard, it is crucial that users apply certain checks:

• Don’t open email attachments until after verifying, with a trusted source, that they are legitimate.
• Make sure you can see the actual file extensions. Unfortunately, Windows allows users to hide them. So, when in reality the file would be called invoice.pdf.vhd the user would only see invoice.pdf. To find out how to do this, see below.
• Use an up-to-date, real-time anti-malware solution that can detect malware hiding in memory.

Showing file extensions on Windows 10 and 11

To show file extensions in Windows 10 and 11:

• Open Explorer (Windows key + E)
• In Windows 10, select View and check the box for File name extensions.
• In Windows 11, this is found under View > Show > File name extensions.

Alternatively, search for File Explorer Options to uncheck Hide extensions for known file types.

For older versions of Windows, refer to this article.

We don’t just report on threats—we remove them

Cybersecurity risks should never spread beyond a headline. Keep threats off your devices by downloading Malwarebytes today.

Last week on Malwarebytes Labs:

• Spammers abuse Zendesk to flood inboxes with legitimate-looking emails, but why?
• Fake LastPass maintenance emails target users
• Under Armour ransomware breach: data of 72 million customers appears on the dark web
• Can you use too many LOLBins to drop some RATs?
• Malicious Google Calendar invites could expose private data
• Fake extension crashes browsers to trick users into infecting themselves
• Google will pay $8.25m to settle child data-tracking allegations
• Firefox joins Chrome and Edge as sleeper extensions spy on users

On the ThreatDown blog:

• How to prevent a rootkit attack

Stay safe!

We don’t just report on threats—we remove them

Cybersecurity risks should never spread beyond a headline. Keep threats off your devices by downloading Malwarebytes today.

A group of cybercriminals called DarkSpectre is believed to be behind three campaigns spread by malicious browser extensions: ShadyPanda, GhostPoster, and Zoom Stealer.

We wrote about the ShadyPanda campaign in December 2025, warning users that extensions which had behaved normally for years suddenly went rogue. After a malicious update, these extensions were able to track browsing behavior and run malicious code inside the browser.

Also in December, researchers uncovered a new campaign, GhostPoster, and identified 17 compromised Firefox extensions. The campaign was found to hide JavaScript code inside the image logo of malicious Firefox extensions with more than 50,000 downloads, allowing attackers to to monitor browser activity and plant a backdoor.

The use of malicious code in images is a technique called steganography. Earlier GhostPoster extensions hid JavaScript loader code inside PNG icons such as logo.png for Firefox extensions like “Free VPN Forever,” using a marker (for example, three equals signs) in the raw bytes to separate image data from payload.

Newer variants moved to embedding payloads in arbitrary images inside the extension bundle, then decoding and decrypting them at runtime. This makes the malicious code much harder for researchers to detect.

Based on that research, other researchers found an additional 17 extensions associated with the same group, beyond the original Firefox set. These were downloaded more than 840,000 times in total, with some remaining active in the wild for up to five years.

GhostPoster first targeted Microsoft Edge users and later expanded to Chrome and Firefox as the attackers built out their infrastructure. The attackers published the extensions in each browser’s web store as seemingly useful tools with names like “Google Translate in Right Click,” “Ads Block Ultimate,” “Translate Selected Text with Google,” “Instagram Downloader,” and “Youtube Download.”

The extensions can see visited sites, search queries, and shopping behavior, allowing attackers to create detailed profiles of users’ habits and interests.

Combined with other malicious code, this visibility could be extended to credential theft, session hijacking, or attacks targeting online banking workflows, even if those are not the primary goal today.

How to stay safe

Although we always advise people to install extensions only from official web stores, this case proves once again that not all extensions available there are safe. That said, the risk involved in installing an extension from outside the web store is even greater.

Extensions listed in the web store undergo a review process before being approved. This process, which combines automated and manual checks, assesses the extension’s safety, policy compliance, and overall user experience. The goal is to protect users from scams, malware, and other malicious activity.

Mozilla and Microsoft have removed the identified add-ons from their stores, and Google has confirmed their removal from the Chrome Web Store. However, already installed extensions remain active in Chrome and Edge until users manually uninstall them. When Mozilla blocks an add-on it is also disabled, which prevents it from interacting with Firefox and accessing your browser and your data.

If you’re worried that you may have installed one of these extensions, Windows users can run a Malwarebytes Deep Scan with their browsers closed.

• On the Malwarebytes Dashboard click on the three stacked dots to select the Advanced Scan option.
  
• On the Advanced Scan tab, select Deep Scan. Note that this scan uses more system resources than usual.
• After the scan, remove any found items, and then reopen your browser(s).

Manual check:

These are the names of the 17 additional extensions that were discovered:

• AdBlocker
• Ads Block Ultimate
• Amazon Price History
• Color Enhancer
• Convert Everything
• Cool Cursor
• Floating Player – PiP Mode
• Full Page Screenshot
• Google Translate in Right Click
• Instagram Downloader
• One Key Translate
• Page Screenshot Clipper
• RSS Feed
• Save Image to Pinterest on Right Click
• Translate Selected Text with Google
• Translate Selected Text with Right Click
• Youtube Download

Note: There may be extensions with the same names that are not malicious.

We don’t just report on threats—we help safeguard your entire digital identity

Cybersecurity risks should never spread beyond a headline. Protect your, and your family’s, personal information by using identity protection.