Which keylogger injects malicious JavaScript into web pages to capture keystroke events such as onKeyUp and onKeyDown?

Which keylogger injects malicious JavaScript into web pages to capture keystroke events such as onKeyUp and onKeyDown?

• A. Hypervisor-Based Keylogger
• B. Memory-Injection-Based Keylogger
• C. JavaScript-Based Keylogger
• D. Form-Grabbing-Based Keylogger

Answer: (C)

This question tests how keystroke data can be captured directly within a web page by running code in the browser. A JavaScript-based keylogger injects malicious script into web pages so it can listen for keyboard events in the browser environment. In JavaScript, events like onKeyDown and onKeyUp fire when a user presses and releases a key. By attaching handlers to these events on input fields or the page itself, the script can record what the user types in real time and often transmit that data back to the attacker. This browser-based approach is distinct from other methods that operate at different layers or capture data in different ways: hypervisor-based or memory-injection-based keyloggers work at the hardware/OS level and aren’t about injecting code into web pages; form-grabbing-based keyloggers focus on intercepting data as forms are submitted or as data is entered into specific fields, rather than logging every keystroke through continuous event monitoring. Thus, the method that injects malicious JavaScript into web pages to capture keystroke events is a JavaScript-based keylogger.

This question tests how keystroke data can be captured directly within a web page by running code in the browser. A JavaScript-based keylogger injects malicious script into web pages so it can listen for keyboard events in the browser environment. In JavaScript, events like onKeyDown and onKeyUp fire when a user presses and releases a key. By attaching handlers to these events on input fields or the page itself, the script can record what the user types in real time and often transmit that data back to the attacker. This browser-based approach is distinct from other methods that operate at different layers or capture data in different ways: hypervisor-based or memory-injection-based keyloggers work at the hardware/OS level and aren’t about injecting code into web pages; form-grabbing-based keyloggers focus on intercepting data as forms are submitted or as data is entered into specific fields, rather than logging every keystroke through continuous event monitoring. Thus, the method that injects malicious JavaScript into web pages to capture keystroke events is a JavaScript-based keylogger.