What Is A Keylogger and How it Works: An Overview

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Maxym Chekalov
Written by
Maxym Chekalov

Updated · Sep 05, 2023

Maxym Chekalov
SEO Specialist | Joined June 2023 | LinkedIn
Maxym Chekalov

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April Grace Asgapo
Edited by
April Grace Asgapo


April Grace Asgapo
Joined June 2023 | LinkedIn
April Grace Asgapo

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Keylogging, often known as keystroke logging, allows a person to spy on the user's computer's keyboard. This is an act where hackers record the user’s strokes on the keyboard. 

According to statistics, 80% of keyloggers cannot be detected by standard anti-virus software. They can get the user’s personal information, such as passwords and bank codes. 

However, a keylogger can also be legitimate software that allows companies or organizations to track employees. This follows what employees do and accomplish. 

Read more about the detailed definition of a keylogger.

Key Takeaways

🔑Keylogger records every stroke on the user’s keyboard. 

🔑This is often used when companies want to track the employee's work. 

🔑It can be in the form of hardware and software. Hardware keyloggers use physical components to spy, while software hides on the user’s device.

🔑Keylogger can be helpful when monitoring the user’s activity without malicious intent to steal the information that this records. 

Defining Keylogger

Defining Keylogger

Keyloggers are malware that record a user’s keyboard strokes and may be downloaded from infected websites. 

Unlike other malware, this is a more dangerous threat to users as it is hard to detect on antivirus programs. They can get confidential information when entered via a keyboard. 

✅Pro Tip:

Microsoft conducted a study in 2019 and discovered that more than 40 million users were using the same passwords. Reusing passwords invites hackers, so avoid doing so.

Hackers can get your PIN codes, passwords, emails, and private conversations. If you don’t know your devices are infected, they can spy on them. 

With weak and outdated passwords, you allow hackers to access your account, and a keylogger can spy on your data.  

There are two definitions of keyloggers. 

  • Keystroke Logging - This will record every key pressed on your keyboard. It can be used to spy on every password you enter. 
  • Keylogger Screenshots - It records your activity on the screen. This is used for tracking conversations and work activities.

Here’s how keylogging works on your device. 

Understanding How Keyloggers Work

Every keystroke transmits information to your computer. The keystrokes that have been logged show everything, including access to online banking and messages. 

Users can get this malware when downloading an infected application or visiting an infected website. Once installed, keyloggers can monitor your activities.  

Here is an example of a keylogger to help you more fully understand them. 

This is an example of a Keylogger with a YouTube video (00-57-1:29). 

Keyloggers use some techniques to infect targets. These are a few of those tactics. 

Phishing Emails

Users might download malware through emails by clicking on the files attached to these phishing emails. The term "malware" refers to several programs that harm and infect computers and computer networks.

Infected Systems

When a user’s device is infected, keyloggers install various malware. This would worsen your vulnerability. 

Trojan Virus

It hides behind legitimate files and applications to infiltrate your device and download a Trojan virus. With this, it can also download keyloggers onto your computer. 

Types of Keyloggers

Keyloggers can propagate through a variety of techniques. As a result, there exist many kinds of keystroke logging. 

Malicious keyloggers fall into several categories; the two primary categories are software and hardware keyloggers

There are various varieties of malware in these two. 

Keystroke Software

It is more common than hardware keyloggers. As this software often hides on users' devices. Some of this tracks your online activities and confidential conversations. 

Here are some examples:

  • Application Programming Interface (API)

This is the most common form of keylogger software. This runs inside the application’s program, recording every user's keystroke. 

  • JavaScript

It can be found on websites where keyloggers are embedded in JavaScript. Once injected into the device, this will record all the keystrokes for the website.

  • Screen Scrapers

This kind of keylogger takes screenshots and records what users do on their screens. 

Hardware Keyloggers

These keyloggers use physical components to execute, such as wiring, devices, etc. This might be much fewer; however, this is also dangerous. 

  • Keyboard

This hardware keylogger is connected to the keyboard itself. It is commonly used on ATM keypads to record users' PIN codes. 

  • Physical Drive

It is typically used via USB drives or memory cards containing keylogger Trojans. 

  • Third-party Recordings

This keylogger attack is from an external recording device. It can be from the public cameras that record computer keyboards. 

Keyloggers Use Cases

A keylogger is one of the main types of malware that terrorizes millions of computers. There are a lot of cases where this specific malware is involved. 

Sumitomo Mitsui Case

In 2005, there was a serious attempt to steal banking data. However, the London police prevented this attack.  The cybercriminals planned to steal $423 million from this bank. 

The keylogger allows criminals to track keystrokes when victims use the bank’s client interface. 

Phishing Case

The Brazilian police arrested 55 people in 2006. They are involved in spreading malicious programs to steal banking information. 

They used a keylogger that activated when users visited their bank websites. 

Safety and Legality of Keylogger

Depending on how it is used, keylogging may be legal or illegal.  Different keylogger characteristics assist in determining whether or not they are lawful. 

There are situations where keyloggers are used to track employees' activity. This situation is legal if the organization asks for their employee's consent.

  • Legal Consensual Keylogger - This type of keylogger asks for the user's consent to record and track the user's computer.

  • Legal Non-Consensual Keylogger - It is legal and illegal. It violates the trust and privacy of the user and the keylogger. However, this doesn’t break the law


Supervising your child’s devices can be legal without their consent, as it is used to protect them from online harm. According to recent data, parental controls are used by 72% of parents to limit their children's screen time

Illegal Use of Keylogging

Keylogging can be illegal when it is used with malicious intent. This can be done to steal, record, and intercept personal information and activity. 

⌛In a Nutshell:

Stealing and using someone’s bank account, social media, or emails without the user’s consent is considered an illegal keylogger. 

Detection and Prevention of Keyloggers

Any attempt by a hacker to enter a computer system and inflict harm is a cyber attack. Even with anti-virus software, your device is only partially secure. It can still threaten your computer, and keyloggers can be a significant danger to you. 

According to Shred Cube, more than 3 million users in the US are victims of identity theft due to keylogging. It is important to have prevention methods.

The following section will focus on some prevention methods to use. 

Read All the Terms Before Accepting the Service

Make sure to read all the terms of the service online before accepting. You should know the consequences and times before signing up. 

Update Your Security Programs

Your security software must be updated to fight the latest threats. This would detect keyloggers properly. 

Do Not Reuse Unknown USB Drives

Reusing unfamiliar drives you get from public spaces can be used as a keylogger. It is suggested that you do not plug in any unknown drives on your computer. 

If you are infected with a keylogger, here are methods to detect it. 

  • Detection of Software Keylogging

You would need a higher standard of security software to scan your device’s system thoroughly. 

  • Detecting Hardware Keylogging

Users can remove the device by hand, as it is a hardware tool. However, you would still need a security program to delete the malware. 

Final Thoughts

Keylogging is the act of recording keyboard strokes and device activity. This can be performed legally or illegally, as it is used to monitor people’s data. An attacker can use a keylogger to download more malware, resulting in identity theft and cyberattacks. 

It falls into two categories: software and hardware. Software is used inside the system, whereas hardware is a tool used outside. 

This malware is one of the most dangerous threats, as it is not detected by standard antivirus software. It would need manual detection or higher antivirus software.


Does a VPN prevent keylogging?

A VPN does not prevent keylogging. It only protects the device's data privacy, not malware. 

Is a keylogger malware or spyware?

A keylogger is spyware because it captures every keyboard stroke and tracks your device. 

Can keyloggers detect copy-paste?

A typical keylogger can record keystrokes and text. Meanwhile, an advanced keylogger can detect if you copy and paste clipboard text. 


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