Chrome Extensions Hacked 3.2M Users at Risk – Act Now!

The attacks took down the browser’s security and put millions of users at risk.

Many of the most popular Chrome extensions were hijacked, and 3.2 million users worldwide would be exposed to this massive data breach. The attacks started in mid-December 2024 by pushing malicious updates to users through popular browser add-ons and involved theft, malware infections, and 2FA bypass.

The incident highlights the browser extensions security vulnerabilities and raises big questions about user and data safety.

The attack affected 35 extensions

Researchers found the large-scale attack saw 35 Chrome extensions taken over. They had most of the affected extensions with millions of downloads, including:

• AI/LLM tools

• Free VPN services

• Ad blockers and other privacy-focused extensions.

You could make a case for the Cyberhaven Extension, a next-gen cyber-incident detection tool. The company’s employee got phished, and within minutes the bug bounty team had found the flaw and fixed it. Citing this as an example, hackers hijack the Cyberhaven Extension and push out malicious updates.

Steps to hack extensions

• Phishing of Developer Accounts—The attacker used spear-phishing to get the credentials of the extension developers.
• Add Code—Once the attacker got full access to the developer accounts, they could push legitimate updates by the developer with malware.
• It is all about Synchronizing Delicacies—The actors stole session cookies to bypass all types of 2FA.

Once they did that, all the extensions became unwitting data harvesters, collecting credentials, tracking web activity, and launching multiple types of malware.

Attack Consequences: Why This Is Bad?

More than just data hoarding: Security experts say compromised extensions do some pretty cool things like

Credentials: Stealing usernames, passwords, and session cookies—equals abuse.

Malware: The hijacked extensions as entry points to inject trojans, spyware, and even ransomware.

Phishing campaigns: Dupe innocent users onto a malicious road full of schemes to collect sensitive personal info.

Bypass 2FA: hackers log in to compromised accounts even if the same account has 2FA.

Google’s Response to Users

Google removed the compromised extensions from the Chrome Web Store. But for the install-existant extensions that were removed, there’s a possibility of being attacked, and so users must take action now.

Actions Required by Users

• Check Installed Extensions: Go to chrome://extensions/ and see if there are suspicious, unknown add-ons.
• Remove the Infected Extensions: Find the ones found in the affected extension group and uninstall them.
• Scan for Malware: Please use a reputable antivirus or anti-malware suite to scan your system for any threats.
• Change Passwords: Passwords that were compromised should be changed immediately for sensitive accounts.
• Enable Advanced Security: Security Keys is the best way to secure the user experience compared to SMS-based 2FA.

Lessons Learned from Past Extension Breaches

Unfortunately, security compromises with extensions are no longer news. An infographic showing incidents for the past two years highlights very possible dangers:

1. 2022: ChromeLoader Incident-injected annoying ads that change search results.

2. 2021: CacheFlow Attack infected over 3 million users worldwide.

3. 2018: Kimsuky Attack—used extensions to spy on targets by North Korean hackers.

Lessons from Past Extension Hijackings

The attacks really show we need to tighten extension security protocols and user vigilance.

Here’s a recap of the training and advice shared by cybersecurity experts:

1. Download Only from Known Sources: Never download extensions from unknown developers.
2. Be Sure Before You Install: Never install extensions that ask for too many permissions.
3. Limit to a Few Extensions: Having fewer extensions is better for security.
4. Review Extensions from Time to Time: Uninstall extensions you think you’ll never use again.
5. Enhanced Safe Browsing in Action: This adds one more layer of protection against phishing and malware.

The Big Picture: Is Browser Extension Generally Safe?

This raises the question of how safe browser extensions are against the benefits they offer and the risks they carry.

Ask experts to tell Google and other browser developers to go further:

• Ask developers to use more thorough verification— The cross-checking of apps so that compromised developer accounts are not common.
• Update Policies for Extension Store— Publish a security audit that digs deeper and cross-checks before a developer’s app is approved.
• Coordinated Removal of Malware Extensions— Get it from the user and leave the detection and removal of malicious extensions to the browser developers.

-> That’s why carefulness is insufficient with online safety. The provider and the end user must then team up and counter any possibility of risk.

Check your Extensions Now!

Thousands of Chrome users now know their extensions are under attack. Go check your browser extensions now for suspicious add-ons and act on them for your digital life.

There are threats that always try to exploit ordinary software. Browser extensions are one of them. Being aware of these can help not only your personal data but online safety as well.

Also Read:

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