How Keylogger Attacks Work and How to Protect Yourself

Simply put, a keylogger captures every keystroke on a computer through a hardware device or software. In other words, it records what you type on your keyboard. It's also called keylogging or keystroke logging. Keyloggers aren't illegal in themselves, but they're often used for malicious purposes.

Positive Uses of Keyloggers

Although keyloggers are often used for illegal activities, there are also some positive use cases. Used well, a keylogger can help monitor specific computer activity.

For example, it can help a remote-work company understand how employees use their computers during working hours. Of course, when using a keylogger like this, you should get the person's consent.

Keystroke logging has also recently been used by researchers as a research tool to study how people write. As you can see, simply recording keystrokes isn't a problem in itself, and there are positive examples too.

Negative Uses of Keyloggers

However, keylogger programs are used far more often in harmful ways. In particular, cyber hackers frequently use them to steal sensitive information from victims, such as credit card numbers, passwords, personal emails, bank account details, and driver's license numbers.

The Two Main Types of Keyloggers

There are two main kinds of keyloggers: hardware versions and software versions. It's important to understand the difference between hardware keyloggers and software keyloggers. The software version is the most common, but it's also a good idea to understand how hardware keyloggers work.

1. Hardware Keyloggers

A hardware keylogger usually consists of a small chip or wire that is physically attached to a computer or laptop. Most hardware keyloggers can be removed easily. That said, you still need to be careful, because even after the chip or wire is removed, the information it collected can still be reviewed with a controlling computer program.

Hardware keyloggers are usually favored by companies that want to manage their employees. Unlike software keyloggers, a hardware keylogger can connect to the computer's BIOS and start recording data as soon as the computer is turned on. Meanwhile, a wireless keylogger sniffer can even record the communication between a wireless keyboard and a computer.

2. Software Keyloggers

Software keyloggers are much harder to detect than hardware keyloggers. Typically, a software keylogger is a program that a hacker has secretly installed on a computer. It can also be downloaded directly on the host computer or remotely, for example through a phishing attack.

The most common software keyloggers only record keyboard activity, but some versions can also take screenshots and log the clipboard. On top of that, there are keyloggers based on JavaScript (injected into websites), APIs (running inside applications), and web forms (recording all data submitted through web forms).

How to Deal with Hardware Keylogger Attacks

Ordinary users are very unlikely to fall victim to a hardware keylogger, especially on devices used at home. In public settings, however, it is possible. Hardware keyloggers usually work through a USB port, so checking the USB area of the computer you're using can be the best prevention.

You can also use your mouse to defend against keylogger attacks when entering sensitive information such as passwords. For example, type the last character of your password first, then move the cursor and type the remaining characters. This way, the keylogger will register the last character as the first one.

If you have no choice but to enter important information in a public place, selecting and replacing text as you type is another option. However, these methods may not work against more sophisticated keyloggers, such as ones that also record mouse activity.

How to Deal with Software Keylogger Attacks

Software keyloggers are hard to detect, but installing a good antivirus program can keep you secure. Anti-keylogger software is specifically designed to detect, remove, and prevent keylogger attacks.

Here are some ways to prevent software keylogger attacks.

• Be careful with email attachments and links.
• Don't click on ads or websites from unknown sources.
• Keep your software applications and operating system up to date.
• Be careful with internet banking and other money-related online activities (including self-proclaimed experts and traders).

How to Detect and Remove Keyloggers

The easiest way to detect a keylogger is to check what's running in your system processes. If you see a program that looks strange, search for it online to find out whether it's a keylogger. Inspecting the traffic your computer sends out is another good method.

Removing a software keylogger isn't as easy as removing a hardware keylogger, but it is possible. Try installing an anti-keylogger program on your system and see whether it can remove it.

That wraps up our detailed look at what keyloggers are and how to detect and respond to them. If your computer is still acting strangely and you suspect the anti-keylogger program can't fix the problem, it may be best to completely format and reinstall your operating system.