How do keyloggers capture our confidential information

Keyloggers: how do they work and how to protect yourself from them

Additional keyboard hardware Additional hardware is installed between the keyboard and the computer - typically directly on the keyboard connection cable. Also called "KeyGrabber", these keyloggers are usually designed as small plug attachments that have an internal memory. The keystrokes are logged in this. KeyGrabber is available for both USB and PS2 connections. Typically, these devices are attached directly to the computer connection and are only noticeable to the user on closer inspection. This is especially true if, for example, the computer connections are not directly visible at the workplace (for example because the tower is on the floor under the desk).   Firmware base These hardware-specific keyloggers log keystrokes at the BIOS level. Often you need physical access to the hardware and at least root access. Firmware-based keyloggers come e.g. B. also in the form of attachments for hardware boards. They are not visible as long as you do not open the affected device.   Keyboard and mouse sniffers These devices read data that is transmitted from a wireless keyboard or mouse to the target system. Since wireless communication is often encrypted, the sniffer then also has to crack the code.   Keyboard attachments Criminals often use this method of keylogging at ATMs. You install an attachment on the input field of the machine. This attachment is often difficult to recognize and is perceived by the user as an integral part of the machine. If customers then enter their PINs and other confidential data, they involuntarily feed it to the keylogger.   Acoustic keyloggers These devices evaluate the noises that a user makes with the keyboard on the computer. After all, pressing each key on a keyboard makes a different sound - but one that is indistinguishable to humans. Acoustic keyloggers also work with statistics on human behavior on the computer in order to reconstruct the text entered by the intercepted user. Typically, however, these devices require a sufficient sample size of at least 1000 keystrokes.   Interception of electromagnetic waves All keyboards generate electromagnetic waves that can have a range of up to 20 meters. Special devices can register and read out these waves.   Video surveillance Traditional video surveillance can also fall under the concept of keylogging. Namely, if the keyboard input is observed with the help of a camera and logged externally.   Physical trace analysis This technology is used less with traditional PC keyboards than with numeric input fields. If certain keys are pressed more often than others, this leaves physical traces that can be used to reconstruct a password, for example.   Smartphone sensors Modern smartphones have so-called accelerometers that can be reprogrammed into special keyloggers. The smartphone can then read out the vibrations that are generated when typing, provided it is close to the target keyboard.