A keylogger is a piece of software or hardware capable of logging a user’s keystrokes on a computer. With such a logger it is possible to access confidential data or spy out passwords.
A keylogger can be implemented either as software or hardware. It is able to record all keystrokes and monitor a user, access confidential data or spy out passwords, PINs and access data. Especially hackers, governmental intelligence services or investigating authorities use this software or hardware.
The logger either stores the recorded data locally on a hard disk, directly in its hardware or transmits it to a remote server via a network connection. Depending on the variant of the keylogger, it records all data or selectively selected keystrokes. Intelligent algorithms ensure that only relevant data such as passwords are selected during selective recording. Many keyloggers spread over the Internet as malicious code and install themselves unnoticed on the respective target system.
Software-based keyloggers operate between the operating system and the keyboard driver of a computer. They take the keystrokes directly from the keyboard driver and send them to both the operating system and the keylogger. Depending on the type, they either store the captured data locally on the hard disk or send it to a specific address on the Internet or network. Software-based loggers are the most common form of keyloggers. They are often part of extensive malicious software designed to compromise a computer or user, which installs itself unnoticed on a computer. Also possible are loggers that are designed as an instance or additional software of a browser. They are able to record all inputs in browser windows.
Hardware-based keyloggers are small physical devices that are mounted between the keyboard and the computer. This requires physical access to the computer. For example, the logger can be equipped with a USB interface on both sides and act as an intermediate plug between the keyboard and the USB socket of the computer. It has an integrated memory in which it collects all recorded data. The logger can be evaluated either by removing the device and attaching it to another computer or by using special software on the monitored computer itself. Some of the hardware keyloggers have their own radio interface and send the data via WLAN or Bluetooth to a target system. Hardware keyloggers are very flexible in use, as they operate completely independent of the installed operating system.
Besides criminals, many parents also use keyloggers to monitor their children’s computers – but some employers also use such tools. In many cases, conventional virus scanners do not find the keylogger. To protect yourself, you need special tools that scan your computer for exactly these attackers, sound the alarm and, best of all, remove them.
Keyloggers are also often installed in Internet cafes. Since it is usually impossible to remove the spying tools on these computers, our tips will help if you generally suspect a keylogger.
These can be easily identified upon closer inspection. They are plugged as an adapter between the USB port of the computer and the mouse/keyboard. If you have such an adapter, it might be such a keylogger. Remove it, or check the brand and type. With some research, you can get certainty.
To trick a hardware keylogger, simply use a virtual keyboard. Use the key combination [Windows] + [R] to open the Run dialog. Type osk.exe there and click OK. This will start the Windows on-screen keyboard. However, this keyboard does not provide protection against software keyloggers.
To find and combat the software-based keyloggers you need to have other software! We could recommend many products, but you should just google it.
Keyloggers are not limited to computers with physical keyboards. They also plague phones and are not so easy to detect since all of them are software-based.