In Chrome, go to chrome://extensions/ , click "Details" on each extension. Look for suspiciously broad permissions like "Read and change all data on websites you visit." A PDF viewer does not need this.

Chrome’s security model isn’t broken—it’s permission-based. The extension above explicitly asks for host_permissions: ["<all_urls>"] . When you install it, Chrome shows a warning: “Read and change all data on all websites.”

While not impossible, it is now extremely difficult for a "stealth" keylogger to pass the Chrome Web Store review process.

The content script keylogger.js listens to DOM keyboard events:

: It is generally legal to install a keylogger on a device you own for personal or parental monitoring, but installing it on another's device without their knowledge to steal data is illegal. Detection and Prevention To protect against unauthorized keylogging extensions:

A keylogger Chrome extension works by injecting malicious JavaScript code into every webpage you visit, allowing it to capture sensitive data like passwords and credit card numbers as you type them. How They Work