Yes, many “Discount Finder” browser extensions can and do watch passwords. While these small tools promise to save money at checkout, they often require permission to “read and change all data” on every website visited. This level of access allows a malicious extension to record every keystroke, capture login credentials, and steal session cookies that keep a person logged into a bank or email account. Even extensions that start as helpful tools can be sold to hackers or updated with hidden code that turns them into digital spies.
The Hidden Power of Browser Extensions
Browser extensions function like small apps that live inside a web browser. They can be very helpful, such as tools that change the screen to a dark mode or automatically find the best coupons while shopping. However, for a discount finder to work, it must be able to see the shopping cart and the checkout page. To do this, it asks for a permission called “Host Permissions.”
When a user clicks “Add to Chrome” or “Add to Firefox,” a small window often appears. It warns that the extension wants to read and change all data on the websites visited. Most people click “Accept” without thinking because they want to save money. In reality, this permission gives the extension a front-row seat to everything done online. If a password is typed into a login box, the extension is technically capable of seeing those characters before they are even sent to the website.
A Concrete Example: Seasonal Shopping
Consider a person shopping for fireworks for a celebration. They might visit a website like Vuurwerkkoopjes to find the best deals on rockets or sparklers. While looking at the prices on the site, a notification might appear suggesting a “Special Savings” extension. The user installs it, hoping for a discount.
Once installed, that extension is not just looking for coupons. It is monitoring the entire browser window. If the user then goes to their bank to check their balance or logs into their email, the extension is still active. Because it has permission to read all data, it can see the username and password entered on those other sites. The user might save a few euros on fireworks, but they could lose access to their entire digital life in exchange.
The Rise of Sleeper Agents
One of the most dangerous trends in 2025 and 2026 is the use of “sleeper agents.” These are extensions that act perfectly normal for months or even years. They build a good reputation, earn thousands of five-star reviews, and gain a large number of users. Once they have a big audience, the developer might sell the extension to a different company, or the original developer’s account might be hacked.
The new owners then push an update that contains malicious code. Because browsers usually update extensions automatically in the background, a person would never know that a favorite coupon finder is now a piece of spyware. Tony Burgess, a security expert at Barracuda Networks, notes that just because an extension has been safe in the past does not mean it is safe today. He explains that attackers use these updates to insert malicious code quietly, turning clean tools into bases for future theft.
What the Data Shows
The scale of this problem is much larger than many people realize. According to research from early 2026, security experts discovered more than 300 Chrome extensions that were leaking or stealing user data. These extensions had been downloaded over 37 million times.
In a separate report from late 2025, researchers found a campaign called RedDirection that affected 16.5 million users. These malicious tools were not just stealing passwords; they were capturing entire “session tokens.” This means even if two-factor authentication (2FA) is turned on, the extension can steal the digital key that proves a person is already logged in.
Davit Asatryan, a Vice President at Spin.AI, said that this discovery shows how important it is to see exactly what is running in a browser. He mentioned that these tools masquerade as legitimate productivity apps while they secretly watch everything a person does.
Common Threats Found in Extensions
- Keylogging: Recording every letter and number typed, including credit card details.
- Cookie Theft: Stealing the files that keep a person logged in so hackers can enter accounts without a password.
- Page Injection: Adding fake login boxes to real websites to trick people into giving away information.
- Traffic Hijacking: Routing internet traffic through a different server to watch activity.
How to Protect Privacy
Deleting every extension is not necessary, but being very careful about which ones are kept is vital. Security experts suggest a “less is more” approach. Fewer extensions mean a smaller chance that one will turn against the user.
Jacob Roach, a tech expert, warns that anything accessed in a browser can potentially be accessed by someone else. He suggests that if someone can get into a browser through an extension, they can open up everything else saved there.
| Step | Action |
| Audit | Review browser settings and delete any extension not used in the last month. |
| Check Permissions | Look for extensions asking to “read and change data on all websites.” If a simple tool asks for this, delete it. |
| Verify the Source | Only download tools from well-known companies and check the “offered by” section in the web store. |
| Use a Standalone Manager | Do not save passwords in a browser. Use a separate, dedicated password manager app instead. |
Moving Forward Safely
The convenience of a small discount is rarely worth the risk of a stolen bank password. As hackers get better at hiding code inside helpful tools, the best defense is a healthy amount of doubt. Before adding a new tool to a browser, it is wise to consider if the tool is truly necessary and if the creator is trustworthy.
