Technology

Fake ad blocker breaks PCs in new malware extension scam

Published

2 weeks ago

February 16, 2026

Fake ad blocker breaks PCs in new malware extension scam

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Fake browser extensions are nothing new, but this one takes things a step further by deliberately breaking your computer to scare you into infecting it.

Security researchers have uncovered a malicious Chrome and Edge extension called NexShield that pretends to be a fast, privacy-friendly ad blocker. Once installed, it crashes your browser on purpose and then tricks you into “fixing” the problem by running dangerous commands on your own PC.

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MALICIOUS GOOGLE CHROME EXTENSIONS HIJACK ACCOUNTS

A fake Chrome and Edge extension called NexShield crashes browsers to trick users into running malicious commands. (Sina Schuldt/picture alliance via Getty Images)

How the NexShield ad blocker scam works

NexShield was promoted as a lightweight ad blocker supposedly created by Raymond Hill, the real developer behind the popular uBlock Origin extension. That claim was false, but it helped the extension look legitimate enough to spread through online ads and search results before it was taken down from the Chrome Web Store.

Once installed, NexShield immediately starts abusing Chrome or Edge in the background. Researchers at Huntress found that it opens endless internal browser connections until your system runs out of memory (via Bleeping Computer). Tabs freeze, CPU usage spikes, RAM fills up and the browser eventually hangs or crashes completely.

After you restart the browser, NexShield displays a scary pop-up warning that claims your system has serious security problems. When you click to “scan” or “fix” the issue, you’re shown instructions telling you to open Command Prompt and paste a command that’s already been copied to your clipboard.

That single paste is the trap. The command launches a hidden PowerShell script that downloads and runs malware. To make detection harder, the attackers delay the payload execution for up to an hour after installation, creating distance between the extension and the damage it causes.

Why this fake browser extension attack is especially dangerous

This campaign is a new variation of the well-known ClickFix scam, which relies on convincing you to run commands yourself. Huntress calls this version CrashFix because instead of faking a system failure, it causes a real one.

In corporate environments, the attack delivers a Python-based remote access tool called ModeloRAT. This malware allows attackers to spy on systems, run commands, change system settings, add more malware and maintain long-term access. Researchers say the threat group behind it, tracked as KongTuke, appears to be shifting focus toward enterprise networks where the payoff is higher.

Home users weren’t the primary target in this campaign, but that doesn’t mean they’re safe. Even if the final payload was unfinished for consumer systems, uninstalling the extension alone is not enough. Some malicious components can remain behind. The biggest danger here isn’t a browser bug. It’s trust. The attack works because it looks like a helpful fix from a trusted tool, and it pressures you to act quickly while your system feels broken.

“Microsoft Defender provides built in protections to help identify and stop malicious or unwanted browser extensions and the harmful behaviors associated with them,” Tanmay Ganacharya, VP of Microsoft Threat Protection, told CyberGuy. “Our security technologies are designed to detect and mitigate tactics like the ones described in this campaign, and they are continuously updated to help keep customers safe. We encourage consumers and organizations to follow our security best practices for reducing exposure to social engineering based threats. Guidance on strengthening your security posture against techniques like this can be found in our blog, ⁠Think Before You Click(Fix): Analyzing the ClickFix Social Engineering Technique, on the Microsoft Security blog.”

We also reached out to Google for comment.

7 steps you can take to stay safe from malicious browser extensions

A few smart habits and the right tools can dramatically reduce your risk, even when malicious extensions slip past official app stores.

1) Only install extensions from trusted publishers

Before installing any browser extension, check the publisher name, official website and update history. Reputable tools clearly identify their developer and have years of user reviews. Be cautious of “new” extensions that claim to come from well-known creators, especially if the name or branding looks slightly off.

2) Never run unknown commands

No legitimate browser extension will ever ask you to open Command Prompt or paste a command to fix an issue. That’s a massive red flag. If something breaks your browser and then tells you to run system commands, close it and seek help from a trusted source.

3) Use a strong antivirus

Strong antivirus software can detect malicious scripts, suspicious PowerShell activity and remote access tools like ModeloRAT. This is especially important because these attacks rely on delayed execution that basic defenses might miss.

The best way to safeguard yourself from malicious links that install malware, potentially accessing your private information, is to have strong antivirus software installed on all your devices. This protection can also alert you to phishing emails and ransomware scams, keeping your personal information and digital assets safe.

Get my picks for the best 2026 antivirus protection winners for your Windows, Mac, Android and iOS devices at Cyberguy.com.

MALICIOUS MAC EXTENSIONS STEAL CRYPTO WALLETS AND PASSWORDS

After freezing your browser, the rogue extension urges users to paste a PowerShell command that installs malware. (Annette Riedl/picture alliance via Getty Images)

4) Use a password manager to limit fallout

If malware gains access to your system, stored browser passwords are often the first target. A password manager keeps credentials encrypted and separate from your browser, reducing the risk of account takeover even if something slips through.

Next, see if your email has been exposed in past breaches. Our No. 1 password manager pick includes a built-in breach scanner that checks whether your email address or passwords have appeared in known leaks. If you discover a match, immediately change any reused passwords and secure those accounts with new, unique credentials.

Check out the best expert-reviewed password managers of 2026 at Cyberguy.com.

5) Keep Windows, Chrome and Edge fully updated

Security updates don’t just patch bugs. They also improve protection against malicious extensions, script abuse and unauthorized system changes. Turn on automatic updates so you’re not relying on memory to stay protected.

6) Consider an identity theft protection service

If malware ever runs on your system, assume personal data could be at risk. Identity protection services can monitor for misuse of your information, alert you early and help with recovery if fraud occurs.

Identity Theft companies can monitor personal information like your Social Security Number (SSN), phone number and email address, and alert you if it is being sold on the dark web or being used to open an account. They can also assist you in freezing your bank and credit card accounts to prevent further unauthorized use by criminals.

See my tips and best picks on how to protect yourself from identity theft at Cyberguy.com.

7) Reduce your online footprint with a data removal service

Many attacks become more effective when criminals already have your personal details. Data removal services help pull your information from broker sites, making it harder for attackers to craft convincing follow-up scams or targeted phishing.

While no service can guarantee the complete removal of your data from the internet, a data removal service is really a smart choice. They aren’t cheap, and neither is your privacy. These services do all the work for you by actively monitoring and systematically erasing your personal information from hundreds of websites. It’s what gives me peace of mind and has proven to be the most effective way to erase your personal data from the internet. By limiting the information available, you reduce the risk of scammers cross-referencing data from breaches with information they might find on the dark web, making it harder for them to target you.

Check out my top picks for data removal services and get a free scan to find out if your personal information is already out on the web by visiting Cyberguy.com.

Get a free scan to find out if your personal information is already out on the web: Cyberguy.com.

FAKE ERROR POPUPS ARE SPREADING MALWARE FAST

Security researchers say the NexShield ad blocker scam deliberately overloads memory to force a system crash. (Photo by Sebastian Gollnow/picture alliance via Getty Images)

Kurt’s key takeaway

Cybercriminals are getting better at blending technical tricks with psychological pressure. Instead of relying on exploits alone, they break things on purpose and wait for you to panic. If a browser extension crashes your system and then tells you to “fix” it by running commands, stop immediately. The safest response is not to fix the problem fast, but to question why you’re being asked to fix it at all.

How many browser extensions are installed on your computer right now? Let us know by writing to us at Cyberguy.com.

Kurt “CyberGuy” Knutsson is an award-winning tech journalist who has a deep love of technology, gear and gadgets that make life better with his contributions for Fox News & FOX Business beginning mornings on “FOX & Friends.” Got a tech question? Get Kurt’s free CyberGuy Newsletter, share your voice, a story idea or comment at CyberGuy.com.

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Technology

Polymarket defends its decision to allow betting on war as ‘invaluable’

Published

3 hours ago

February 28, 2026

Press Room

Polymarket defends its decision to allow betting on war as ‘invaluable’

It might be World War III, but at least I won $20. | Image: Polymarket / The Verge

Polymarket has been allowing people to bet on when the US would strike Iran next. Obviously, now that it’s actually happened and people have died, the prediction betting market is feeling some pressure. The site has been at the center of controversy before, including suspicions of insider trading on the Super Bowl halftime show and the capture of Venezuelan President Nicolás Maduro.

In a statement posted on its site, Polymarket defended its decision to allow betting on the potential start of a war, saying that it was an “invaluable” source of news and answers, before taking shots at traditional media and Elon Musk’s X. The statement reads:

…

Read the full story at The Verge.

Technology

Google dropped dark web monitoring: Should you care?

Published

4 hours ago

February 28, 2026

Press Room

Google dropped dark web monitoring: Should you care?

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Google has officially discontinued its Dark Web Report feature, a free tool that once scanned known dark web breach dumps for personal information tied to a user’s Google account. The service delivered notifications when email addresses and other identifiers appeared in leaked datasets.

According to Google’s support page, the system ceased scanning for new dark web data Jan. 15, 2026, and the reporting function was removed entirely on Feb. 16, 2026, meaning users can no longer access the feature.

The company said the decision reflects a shift toward security tools it believes provide clearer guidance after exposure, rather than standalone scan alerts.

If you previously relied on the free dark web scan as an early warning signal for leaked data, this change removes one of your sources.

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Google officially ended its Dark Web Report tool, removing free breach alerts tied to user accounts. (Kurt “CyberGuy” Knutsson)

So what did users really lose?

Google’s Dark Web Report acted as a basic exposure scanner. It checked whether personal information linked to a Google account had surfaced in known breach collections circulating on the dark web.

When a match is found, users receive a notification identifying which type of data appeared in a leak. Depending on the data breach, that could include an email address, phone number, date of birth or other identifying details commonly harvested during large-scale hacks.

The report did not display stolen credentials or provide access to the leaked database itself. It also did not trace the origin of the compromise beyond referencing the breached service when available.

After an alert was issued, the next steps were left to the user. Google recommended actions such as changing passwords, enabling stronger authentication methods and reviewing account security settings. With the tool now removed, that automated breach check tied directly to a Google account is no longer available.

What you still have access to

Google directs users to its Security Checkup, a dashboard that scans your account for weak settings and unusual sign-in activity.

Its built-in Password Manager includes Password Checkup, which scans saved credentials against known breach databases and prompts you to change exposed passwords. Google also supports passkeys and two-factor verification to lock down account access.

The Results About You tool lets users search for personal information in Google Search and submit removal requests for certain publicly indexed details.

149 MILLION PASSWORDS EXPOSED IN MASSIVE CREDENTIAL LEAK

Without the automatic scan, users must now check for leaked data using other security tools. (iStock)

Alerts don’t always mean protection

Once personal information is compromised, it often ends up far beyond the breach itself. Stolen credentials and identity data are regularly trafficked on underground platforms where buyers can search for information tied to real people.

The BidenCash dark web marketplace was taken down by U.S. authorities in June 2025, and the Justice Department confirmed that the platform peddled stolen personal information and credit card data.

These illicit markets operate with a level of organization not unlike legitimate online stores. Search tools and bulk data sets are up for grabs and can be used to target any online account. This makes credential stuffing easier, where attackers test leaked passwords across multiple services in hopes of barreling into your account.

A breach alert tied to a dark web scan points to a leak at one moment in time; it does not follow whether that information has been sold to third parties or used in subsequent fraud attempts. For everyday users, this means that just knowing your data appeared in a leak doesn’t help much.

THINK YOUR NEW YEAR’S PRIVACY RESET WORKED? THINK AGAIN

Stolen personal information can circulate for years, making ongoing monitoring more important than a one-time alert. (Kurt “CyberGuy” Knutsson)

Identity monitoring may be a better option

With Google’s scan gone, some people may consider dedicated identity protection services instead. Many of these services offer continuous monitoring of your personally identifiable information and send alerts about changes to your credit reports from all three major U.S. credit bureaus. That can include notifications about new inquiries, newly opened accounts and monthly credit score updates. Some plans also monitor a broader range of personal identifiers, such as driver’s license numbers, passport numbers and email addresses.

Beyond credit monitoring, certain services track linked bank, credit card and investment accounts for unusual activity. They may also monitor public records for changes to addresses or property titles and alert you if your information appears in those filings.

Many providers include identity theft insurance to help cover eligible out-of-pocket recovery costs. Coverage limits vary by plan and provider. Additional features often include spam call and message protection, a password manager, a virtual private network (VPN) and antivirus software.

No service can prevent every form of identity theft. However, ongoing monitoring and recovery support can make it easier to respond quickly if your information is misused.

See my tips and best picks on Best Identity Theft Protection at Cyberguy.com.

Kurt’s key takeaways

Google’s decision to drop its Dark Web Report may seem small. But it removes a tool many users relied on. For some, those alerts were the first warning that their data appeared in a breach. That automatic scan is now gone. Google still offers Security Checkup, Password Checkup, passkeys and two-step verification. However, none of them actively scan dark web breach dumps for you. Stolen data does not disappear. Criminals copy, sell and reuse it. One alert shows a single moment. Ongoing identity theft monitoring helps you stay aware over time.

Now that Google has dropped its dark web monitoring feature, will you actively check your data exposure or assume someone else is watching it for you? Let us know your thoughts by writing to us at Cyberguy.com

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Technology

Xiaomi 17 is a small(ish) phone with a big(ish) battery

Published

15 hours ago

February 28, 2026

Press Room

Xiaomi 17 is a small(ish) phone with a big(ish) battery

Xiaomi has just given a global launch to two of its latest flagship phones, the Xiaomi 17 and 17 Ultra, along with a Leica-branded Leitzphone edition of the Ultra. There’s no sign, however, of the 17 Pro, which launched in China with an additional display mounted next to the rear cameras.

The 17 and 17 Ultra will apparently be available soon in the UK, Europe, and select other markets. The 17 — pitched as a rival to the likes of the iPhone 17 and Samsung Galaxy S26 — will cost £899 / €999 (about $1,200), while the larger and more capable Ultra starts from £1,299 / €1,499 ($1,750). The limited-edition Leitzphone will be substantially more expensive at £1,699 / €1,999 ($2,300), though it includes 16GB of RAM and 1TB of storage, along with a few extra accessories.

I like the simple, sleek aesthetic of the phone.

Photo of Xiaomi 17 homescreen on a wooden table outdoors

The 6.3-inch display isn’t tiny, but it does make the phone small by modern standards.

All three of the phone’s rear cameras are 50-megapixel.

The 17 is an extremely capable small-ish flagship, with a 6.3-inch OLED display, Qualcomm Snapdragon 8 Elite Gen 5, and large 6,330mAh silicon-carbon battery (though sadly smaller than the 7,000mAh version launched in China). I won’t be writing a full review of the 17, but did spend a week using it as my main phone, and found that the battery cruised past the full-day mark, though wasn’t quite enough for two full days of my typical usage. That’s far better battery life than you’d find in similarly sized phones from Apple, Samsung, or Google.

The cameras impress too, with 50-megapixel sensors behind each of the four lenses, selfie included. Pound for pound, you won’t find many better camera systems in any phone this size.

1/10

I’ve been largely impressed by the Xiaomi 17’s cameras.

The Ultra, unsurprisingly, takes things to another level. It’s much larger, with a 6.9-inch display, and weighs a hefty 218g. Despite that, the 6,000mAh is actually smaller, though I found it delivered pretty similar longevity.

Photo of Xiaomi 17 and 17 Ultra on a table, closeup on the cameras

The 17 Ultra is larger in just about every respect, but strangely has a smaller battery.

The enormous camera is, as ever for Xiaomi’s Ultra phones, the highlight. There are 50-megapixel sensors for each of the main, ultrawide, and selfie cameras, with a large 1-inch-type sensor behind the primary lens. The periscope telephoto is even more impressive: 200-megapixel resolution, a large 1/1.4-inch sensor, and continuous optical zoom from 3.2x to 4.3x, the equivalent of 75-100mm. Xiaomi isn’t the first to pull off a true zoom phone — Sony’s Xperia 1 IV got there first in 2022 — but the telephoto camera here is far more capable than that phone’s, with natural bokeh and impressive performance even in low light.

Photo of Xiaomi 17 Ultra Leitzphone outdoors

This is the Leica-branded Leitzphone version of the 17 Ultra.

The camera capabilities are supported by Xiaomi’s ongoing photography partner Leica, but it’s the pair’s Leitzphone that really emphasizes that. Slightly redesigned from the 17 Ultra Leica Edition that was released in China last December, this includes Leica branding across the hardware and software, a range of Leica filters and shooting styles, and a rotatable rear camera ring that can be used to control the zoom. It’s the first Leica Leitzphone produced by Xiaomi — after a trio of Japan-only Sharp models — and comes with additional branded accessories, including a case with a lens cap and a microfiber cleaning cloth.

Xiaomi has plenty of other announcements alongside the 17 series phones at MWC this year, including a super-slim magnetic power bank, the Pad 8 and Pad 8 Pro tablets, and a smart tag that supports both Google and Apple’s tech-tracking networks.

Photography by Dominic Preston / The Verge

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