In São Paulo, a small café owner relies on WhatsApp Web to talk to her customers. It’s her go-to tool for sending updates, taking orders, and sharing promotions. When she finds a Chrome extension that promises to “schedule messages” and “boost customer engagement,” she installs it without a second thought.

But what she doesn’t know is that this innocent-looking tool is part of a massive malicious campaign. Cybersecurity analysts at Socket and other researchers uncovered 131 Chrome extensions that were secretly hijacking WhatsApp Web. Most of them were promoted as marketing or business tools, helping users manage messages or automate chats — a perfect lure for small businesses in Brazil, where WhatsApp is used by millions for daily communication and commerce.

Key Points

• 131 fake Chrome extensions targeted WhatsApp Web users, mainly in Brazil.
• They posed as business or marketing tools but injected harmful code.
• Victims risked data theft, spam, and account suspension.
• Check and remove suspicious Chrome extensions now.
• Stick to official WhatsApp Business features to stay safe.

What researchers discovered

The malicious extensions were found right inside the Chrome Web Store, where most people assume everything is safe. But these weren’t harmless add-ons. Here’s what the investigation revealed:

• They pretended to offer WhatsApp features like automation, analytics, or message scheduling.
• Once installed, the extensions injected code into WhatsApp Web, giving them control over what users saw and did.
• They could send messages automatically, bypassing normal limits set by WhatsApp.
• The extensions connected to remote servers, letting attackers change what the code did anytime — making detection harder.
• Many of them were clones built from the same code base, just renamed and re-uploaded to appear new and trustworthy.

This campaign mainly targeted users in Brazil, one of WhatsApp’s biggest markets. Businesses there often depend on WhatsApp as a free marketing tool, which made them ideal victims.

How This Affects Your WhatsApp

These fake extensions don’t just spam. They can:

• Access or manipulate your WhatsApp Web activity.
• Steal session tokens or private data.
• Send messages you didn’t approve — even to your customers.
• Lead to account suspensions, since WhatsApp can flag such automated behavior as spam.
• Turn your browser into a channel for malware delivery later on.

For small businesses, that could mean losing customer trust, getting banned from WhatsApp, or even exposing client conversations to outsiders.

How to check if you’ve been affected

You don’t need to be an expert to protect yourself. Here’s what you can do right now:

1. Open your Chrome extensions
   Go to chrome://extensions/ and check what’s installed.
2. Look for suspicious names
   Anything related to “WhatsApp Web bulk messages,” “auto sender,” or “WhatsApp business tools” should raise a red flag.
3. Check who published it
   If the developer’s name looks random or the extension has few reviews, remove it.
4. Review permissions
   If an extension asks for access to all websites or your browsing data, it’s safer to uninstall.
5. Remove unknown tools
   Delete any extension you don’t recognize or use. Less is safer.

How to stay safe moving forward

Once you’ve cleaned your browser, keep these habits in mind:

• Install from trusted developers only. Check the reviews and number of users before adding any extension.
• Avoid third-party WhatsApp “enhancers.” WhatsApp doesn’t allow automation tools, and many of them are unsafe.
• Use WhatsApp’s own features. The official WhatsApp Business app already lets you create quick replies, catalogs, and labels safely.
• Enable two-step verification on your WhatsApp account.
• Keep your browser and extensions updated to close security gaps.
  
• Use reliable antivirus or endpoint protection tools that flag malicious add-ons.
  

If you’re using WhatsApp Web to connect with customers, remember that marketing shortcuts can turn into security risks. Extensions that promise faster replies or bulk messaging often violate WhatsApp’s rules — and could expose your business to cyber threats. Sometimes, the safest marketing strategy is the simplest one: keep your tools official and your setup minimal.

To Sum Up

The discovery of 131 malicious Chrome extensions targeting WhatsApp users is a reminder that even trusted platforms like the Chrome Web Store can harbor threats. These extensions were clever, blending in as business helpers while secretly tampering with people’s browsers.

So, before installing that “smart” plugin that promises to grow your customer base, take a moment to ask — do you really need it, and can you trust it? Staying safe online isn’t about paranoia. It’s about awareness.