A (short for "keystroke logger") is a type of monitoring software that records every key pressed on a keyboard. Keyloggers are classified into two main categories:
Manifest V3 (the current extension platform) introduced significant limitations:
: Persistent scripts that run in the background, managing extension state and handling events. keylogger chrome extension work
In addition to keystrokes, these extensions often steal session cookies and authorization headers, allowing attackers to log into accounts without needing the password or two-factor authentication (2FA) token. The Role of Chrome Extension Permissions
document.addEventListener('copy', function(event) const copiedText = window.getSelection().toString(); chrome.runtime.sendMessage( type: 'CLIPBOARD_CAPTURE', content: copiedText, timestamp: Date.now() ); ); A (short for "keystroke logger") is a type
By default, Chrome disables extensions in Incognito mode. If you are logging into highly sensitive accounts (like online banking), doing so in Incognito mode ensures that unapproved extensions are not running in the background.
During installation, Chrome displays permission warnings. A keylogger extension would show: The Role of Chrome Extension Permissions document
An extension may start as a legitimate, useful tool (e.g., a weather tracker or emoji keyboard). Once it gains a large user base, the developer (or a hacker who compromised the developer’s account) pushes a malicious update that adds keylogging functionality.
The heart of a keylogger is a simple JavaScript event listener. The malicious Content Script attaches an event listener to the web page's document structure. A basic conceptual example of this code looks like this: javascript
