What Are Keystroke Loggers and How Do They Work?

What Are Keystroke Loggers and How Do They Work?

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Updated on Apr 23, 2024 15:44 IST

What occurs on your keypad doesn’t remain there. Username and password, passwords, bank account numbers, and private messages are all captured by keystroke loggers. So, what exactly is a keystroke logger?



In this article, we will discuss in-depth keystroke loggers. But, before moving on that, let’s go through the topics that we will be covering in this blog:

What are keystroke loggers?

A keystroke logger, also known as a keylogger or keyboard capture, is a surveillance technology that monitors and records each keystroke made on a particular computer. This helps to monitor one’s computer activity quietly while they use their devices normally.


You can also use keystroke loggers for legitimate purposes, such as software development feedback. But, keystroke loggers, on the other hand, can allow cybercriminals to eavesdrop on you or listen through your smartphone’s microphone.

Must Explore- What is Cybersecurity?

Let’s take an example to understand better. An attacker may send a phishing email claiming that a critical update is available that staff members must install in order to continue using the company’s online services. Several employees are duped into downloading and installing the malware. Thus, enabling attackers to grab corporate data by tracking login credentials.

You can also explore – What is a phishing attack?

Types of keystroke loggers? 

There are two types of keystroke loggers. Those two are:

  • Hardware keystroke logger
  • Software keystroke logger

Hardware keystroke logger: A hardware keystroke logger is a tiny device that connects the keyboard to the computer. The device looks like a standard PS/2 keyboard connector. As a result, hiding the device is relatively simple for an individual who desires to oversee a user’s behavior.

Software keystroke logger: A software keystroke logger is software that was either purposefully downloaded by someone who wanted to monitor activity on a specific computer, or unknowingly downloaded by the user as disguised as a legitimate file or folder, etc.

How does a keystroke logger works?

A keystroke logger infiltrates your computer by hiding inside a Trojan, phishing mail, or other malware. A keystroke logger saves your keystrokes in small files that the attacker can view. The files could be emailed to the hacker regularly or put online on a website. If, on the other hand, the attacker is using a hardware keystroke logger, the files may be saved on the computer until the hacker retrieves the keylogging device.

You can also explore – What is a Trojan horse attack?

Keystroke loggers can monitor and record all that you write, posing a significant risk to the confidentiality of your information. Nowadays, almost everyone enters confidential information on computers, from internet banking credentials to aadhar card numbers. And an attacker can easily use logged keystrokes to assemble user behaviors and private data. A hacker with such information is only one step away from committing identity fraud, selling your private data on the dark web, or exposing your personal information, among other things.

A real-life example of a keystroke logger 

The notable theft of over $1 million from customer accounts at the Scandinavian bank Nordea was one of the most popular keylogging incidents. In August 2006, Nordea customers began receiving emails from the bank recommending that they download spam detection software allegedly attached to the message.

When the victim registered for Nordea’s online service, the trojan would display an error message requiring them to re-enter the login information. The keystroke logger that came with the trojan will further record data entered by the customers and send it to the attacker’s server.

Signs that our system may be infected with a keystroke logger

Keylogger warning signs are similar to those seen in other malware types. Some of the signs that warn us that a keystroke logger may infect our system are:

  • Changed settings: If your browser suddenly has a new homepage, icons, etc., it may indicate malicious software, such as a keystroke logger.
  • Slow performance: If your computer suddenly begins transmitting all of your keystrokes to a hacker, your overall performance will suffer.
  • Unexpected crashes and freezes: Because of the processing power required for recording, your other apps may crash and freeze more frequently than usual.
  • Strange redirects: If you type in a search and it redirects you to an unexpected search engine that doesn’t appear correct, it could be a malicious redirect.

Methods to detect keystroke loggers on a computer 

There are two most common methods to detect keystroke loggers on a computer. Those two methods are:

Using task manager: If a keystroke logger is currently active, it will be visible in the task manager. To confirm that: you must follow the steps outlined below.

  • Press Ctrl + Alt + Del to load the task manager
  • When the task manager loads, navigate to the process tab.
  • Look for any malicious file with a suspicious description in the list to spot a keystroke logger.

Doing a full malware scan: The anti-malware software will check the hard drive folders for any malicious software hiding on the computer.

How to protect against a keystroke logger?

Some of the most common ways to protect against a keystroke logger are:

Avoid clicking on pop-ups: An attacker can sometimes use pop-ups (adware) to infect your system. Pop-ups can contain malware (adware), and when you click on them, a keystroke logger may be downloaded without your knowledge.

Only download software from reputable sources: Keystroke logger software may be bundled with legitimate software on third-party download sites. As a result, always avoid downloading from untrustworthy sources.

Avoid opening attachments from unknown people: If you receive an attachment from an unknown contact, proceed with caution as the attachment could contain malware that installs a keystroke logger on the system.

Keep your apps and software up to date: Updates include bug fixes and security patches that, among other things, prevent exploits.

Use antivirus software: Implementing strong antivirus software is the best defense against all types of malicious software, such as a keystroke logger.

Use safe browsing: It is a service by google that protects website owners and users from malicious websites and downloads.

You can also explore – What is Safe Browsing & How to Turn It On?


Even though keystroke logger developers market their products as legitimate software, most people use keystroke loggers for stealing personal user data and in political and industrial espionage. Attackers use keystroke loggers, along with phishing and social engineering, which are currently one of the most popular methods to commit cyber fraud. So, rather than being sorry later, use the preventive measures listed above.


What exactly are API-based keystroke loggers?

It is a software keystroke logger that intercepts the signals sent from each keypress to the program you're typing in.

What are kernel-based keystroke loggers?

It is also a software keystroke logger that infiltrates the system's core in order to gain admin-level access. These loggers can circumvent security and gain unrestricted access to everything entered into your system.

Is it possible to detect a keystroke logger?

Yes, it is possible. Antivirus software can detect keystroke loggers. When antivirus software scans your device for keystroke loggers and other types of malware, it acts as a keystroke logger detector.

Are keystroke loggers prohibited?

Installing a keystroke logger on your device is legal, but installing a keystroke logger behind the owner's back in order to steal their data, is illegal.

How do hackers put keystroke loggers in place?

Keystroke loggers can be installed using a web script. This is accomplished by exploiting a vulnerable browser and launching keystroke logging when the user visits the malicious website.

Is it possible to install a keystroke logger on a cell phone?

Yes, it is possible. The keystroke logger can work with the majority of modern Android phones. It can be installed, preferably without the need for root access.

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