What is a Keylogger?
A keylogger is software or hardware designed to monitor and record keystrokes on a computer. It is commonly used covertly to steal sensitive information such as passwords without the user's knowledge.
The most commonly used type of keylogger is software-based. This type is often installed on a target user's PC as part of malware, where it runs in the background, monitoring and recording keyboard inputs. Typically, it spreads as a trojan malware and communicates with external servers to unlawfully transmit stolen information. Such keyloggers can usually be detected and removed by antivirus software.
In contrast, hardware-based keyloggers also exist. These are often designed as USB devices placed between the keyboard's USB connector and the PC's USB port. Hardware keyloggers require physical access to the target computer to be installed but are not detectable by antivirus software, making them highly dangerous. Some hardware keyloggers even come equipped with Wi-Fi capabilities to transmit collected data externally.