While being more difficult to implement, they can be more flexible for the attacker as they are OS-independent. Other hardware keyloggers can be implemented via USB flash drives or as a fake connector for the keyboard that sits between the keyboard cable and the PC. A malicious insider could install such a keylogger at the factory level. Some hardware variants can be installed during the manufacturing process, including BIOS-level keyloggers. This can be done either during the manufacturing process or after deployment. Hardware keyloggers often require the attacker to have physical access to the target machine. Hardware-based keyloggers are less common, as they are more difficult to implement on the target machine. There also are kernel-level keyloggers, man-in-the-browser keyloggers and other more complex variants. It generally has the ability to impersonate an API on the target machine’s operating system, which allows the keylogger to record each keystroke as it’s made. Such a keylogger is easier to get onto a target machine, since it typically doesn’t require physical access to the machine. It is often installed as part of a larger piece of malware, such as a Trojan or rootkit. The most commonly used keylogger is a software-based tool. There are software-based and hardware-based keyloggers.

The keylogger can either store the recorded data locally or send it to a remote PC controlled by the attacker. A keylogger is any piece of software or hardware that has the capability to intercept and record input from the keyboard of a compromised machine without the user’s knowledge.

What is keylogging