Key Logger

A key logger is malicious software or hardware that records everything typed on a device, capturing passwords, two-factor backup codes, and, most damaging in crypto, seed phrases entered on a keyboard. Software keyloggers arrive through infected downloads, email attachments, fake applications, and malicious browser extensions; hardware versions are small devices physically inserted between a keyboard and computer, mostly a risk on shared or public machines.

For crypto users the worst-case scenario is typing a seed phrase into a compromised computer, for example while restoring a software wallet. A keylogger sends those words to an attacker, who can reconstruct the wallet and take everything, possibly waiting until the balance grows. Exchange passwords are also valuable, though two-factor authentication limits their usefulness on their own. Modern variants go beyond keystrokes, capturing screenshots and clipboard contents as well.

The strongest protection is structural: hardware wallets keep seed phrases and private keys off the computer entirely, since the phrase is generated and entered on the device itself and transactions are signed internally. Beyond that, standard hygiene applies: install software only from official sources, keep systems updated, be wary of browser extensions, and never enter a seed phrase on any internet-connected device. A common misconception is that antivirus software guarantees safety; detection lags behind new malware, so the goal is to ensure that even a fully compromised computer has nothing worth stealing to record.