---
title: "Keylogger"
description: "A keylogger is software or hardware that records keystrokes to steal passwords and data. Learn the types of keyloggers and how to protect yourself."
url: "https://nodea.io/en/glossary/keylogger"
lang: "en"
updated: "2026-07-13"
---

# Keylogger

> A keylogger is malicious software or a hardware device that secretly records keystrokes, capturing passwords, card numbers and other sensitive data typed by the victim.

A **keylogger** (keystroke logger) is a type of spyware or a hardware device whose job is to secretly record everything a user types on the keyboard. The captured keystrokes — logins, [passwords](https://nodea.io/en/glossary/password), payment card numbers, message contents — are then sent to an attacker. Keyloggers are among the most dangerous identity-theft tools because they run in the background and stay unnoticed for a long time.

## How a keylogger works

Depending on its form, there are two main types:

- **software keyloggers** — applications installed on a system, usually without the user's knowledge, that intercept keyboard events at the operating-system, browser or kernel level; they often spread as part of trojans, [adware](https://nodea.io/en/glossary/adware) or attachments in [phishing](https://nodea.io/en/glossary/phishing) campaigns;
- **hardware keyloggers** — physical devices plugged in between the keyboard and the computer or mounted inside the hardware; antivirus software can't detect them, but they require physical access to the machine.

Advanced variants record not just keystrokes but also screenshots, clipboard contents and visited pages, building a complete picture of the victim's activity.

## Practical application

In criminal hands, keyloggers are used to hijack bank accounts, email, site admin panels and social-media profiles. They are especially dangerous for administrators and anyone managing infrastructure, because captured credentials for a server or hosting panel open the door to further attacks such as [ransomware](https://nodea.io/en/glossary/ransomware).

Protection relies on several layers: up-to-date antivirus and anti-malware, current system patches, caution with attachments and links, using a password manager (which fills fields automatically, bypassing keyboard entry) and — crucially — [two-factor authentication](https://nodea.io/en/glossary/two-factor-authentication), which neutralises a stolen password string on its own. It's worth noting that keyloggers can also be legitimate — as parental-control or workplace-monitoring tools used with the user's consent.

### How can I tell if my computer has a keylogger?

Hardware keyloggers may appear as a small adapter between the keyboard and a USB port. Software ones are harder to spot — they may cause system slowdowns, unusual network activity or unfamiliar processes. An up-to-date antivirus and anti-malware scan is the most reliable way to detect them.

### Does two-factor authentication protect against keyloggers?

It significantly limits the damage. Even if a keylogger captures your password, without the second factor (an app code or a hardware key) an attacker can't log in. That's why 2FA is one of the most effective defences when login credentials alone are leaked.

## Related

- [Phishing](https://nodea.io/en/glossary/phishing)
- [Ransomware](https://nodea.io/en/glossary/ransomware)
- [Password](https://nodea.io/en/glossary/password)
- [Two-Factor Authentication (2FA)](https://nodea.io/en/glossary/two-factor-authentication)
- [Adware](https://nodea.io/en/glossary/adware)

---

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