What is a keylogger?
Definition
A keylogger is software that records what you type, usually to capture passwords and other sensitive information, and sends it to someone else.
- Category
- Attacks
- Also called
- key logger, keystroke logger
- Last updated
A keylogger sits on a device and logs every key you press: passwords, messages, search terms and card numbers. NIST's glossary defines a key logger as software that tracks keyboard input, usually to capture passwords or encryption keys so that other protections can be bypassed.
Keystroke monitoring is the same idea used openly. NIST describes it as recording what a user types along with how the computer responds. Organizations sometimes do that on their own systems, with notice. The problem is the hidden version.
How one ends up on your device
A keylogger is a kind of malware, so it arrives the same ways other malware does: a link or attachment in a phishing message, a download from an untrustworthy site, or an app you installed without knowing what it did. The FTC describes malware as harmful software installed on your device without your knowledge.
Keyloggers are also part of stalkerware, apps that someone with physical access installs on a partner's or family member's phone to watch them. The FTC notes that such apps can hide in the settings under innocent names.
Why it matters
Strong passwords don't help if every keystroke is copied as you type. The attacker doesn't have to guess anything or crack any hash: they read the password directly, along with the other things you type. They can then log in as you.
Warning signs
Keyloggers are meant to be invisible. The FTC lists general signs of malware: a slower device, faster battery drain, unexpected data use and unexpected restarts. These can also have harmless causes, so treat them as a reason to check, not as proof.
Keylogger vs. related terms
- Spyware is the wider group of software that spies on you. A keylogger is one kind.
- Malware is any harmful software.
- Phishing steals credentials by tricking you. A keylogger steals them by watching you.
How to protect yourself
- 1
Keep devices and apps updated
Updates close the holes malware uses. Turn on automatic updates for your operating system and browser.
- 2
Install software only from trusted sources
Use official app stores and the vendor's own website, and don't open attachments you didn't expect.
- 3
Use two-step verification
A stolen password is less useful when a second step is required. Security keys and authenticator apps are stronger than text codes.
- 4
Run a scan with up-to-date security software
If you suspect a keylogger, scan the device, then change your passwords from a different, clean device.
- 5
Think safety first if someone close to you may be behind it
The FTC advises contacting a domestic violence advocate before removing stalkerware, because an abuser may react if they lose access.
See where your personal data is exposed
Serus finds it on data brokers and people-search sites and removes it.
Frequently asked
How do I know if I have a keylogger?
They are designed to hide. A slow device, odd battery drain or unexpected data use can be signs, but a security scan is a better check. If you suspect one, use another device to change your passwords.
Can a keylogger steal my password if I use a password manager?
It can still capture what you type, such as a master password. Autofill reduces typing, and two-step verification limits what a stolen password can do.
Is a keylogger the same as spyware?
A keylogger is one type of spyware. Spyware can also track location or turn on a camera or microphone.
Sources
Something wrong or out of date? Tell us and we'll re-check it.