What is a keylogger?
A keylogger (from the English "key" for "keyboard key" and "logger" for "recording device") is a program or device that intercepts and records data input from a keyboard. Some keyloggers can also record touches and swipes on a phone's touchscreen, but most often they are used to record computer keyboard inputs. This program records and stores stolen information on the infected computer, then transfers it to the attacker's device. Typically, keyloggers are malicious programs, but in some cases, they are used by governments, police, or other entities.
Types of Keyloggers
There are many varieties and modifications, as is typical for such programs. However, two main types can be identified:
1. Software
This type of keylogger is part of another malicious program or virus. One of the most common types of software keyloggers can deploy a ready-made API on the target device that records every keystroke.
2. Hardware
These programs need to be physically installed, and the hacker must have direct access to the computer, which significantly increases the risk of being detected. However, sometimes such programs are implemented at the manufacturing level or even integrated into the BIOS. Another method of direct connection is through infected USB devices.
How does a keylogger infect a system?
The principle is the same as with other viruses and malicious programs. They replicate themselves and spread through networks. Trojan keyloggers appear as regular software (or hide within it). Rootkits may contain keylogger elements, making them difficult to detect even with good antivirus software. Hackers often distribute malware through drive-by downloads—scripts that execute upon visiting a malicious website, or phishing—where you are tricked into installing malicious software or clicking on a link to a site with drive-by downloading. Law enforcement and police typically conduct highly targeted attacks against individuals using personalized spear-phishing tactics and employ social engineering to deceive the victim into installing a malicious keylogger.
Ways to protect against keyloggers
All the usual precautions for protecting yourself from malicious software apply to keyloggers as well: - use good antivirus software, - do not open emails from unknown sources, - do not click on links you are unsure about, - do not install software from unreliable websites, - do not respond to suspicious emails or SMS, - use a reliable VPN service
How to recognize and remove a keylogger?
This is a tricky task. Keyboard spies do not extract specific files to send them to a hacker's device, nor do they destroy data on your computer. They operate stealthily. Here, antivirus programs come to the rescue, capable of detecting all keyloggers marked as malicious software and removing them. However, if a keylogger is designed for a targeted attack on a specific user, the antivirus may not notice it due to its absence in the database of malicious software. Nevertheless, sooner or later, they are detected. For example, as soon as they start unauthorized sending of data to an unknown remote server. If you suspect that your keyboard actions are being recorded, you can boot the OS from a disk or USB, and also use a virtual keyboard. And, of course, it's essential to immediately download a quality antivirus if you don't have one for some reason.