The past several decades have seen an arms race in computer security. As cunning new viruses are developed, consumers fight back with more and more defensive measures. But keyloggers, pieces of software designed to record computer use and secretly send it to a host, have hardly changed. Those without adequate defense may be completely unaware that a keylogger, also referred to as a trojan, has settled in on their computer.

How Keyloggers Work

Keyloggers are very small, almost unnoticeable applications. After sneaking onto a computer they record anything from keystroke to clicking patterns and then send the information back to a host computer.

Types

Not all keyloggers are bad. While a keylogger generally refers to a malicious piece of software, many parents use similar applications to monitor and protect their children on the Internet.

Malicious Uses

Malicious keyloggers are used to collect private information such as bank account passwords, social security numbers and credit card numbers.

Avoiding Keyloggers

Keyloggers are especially common on file-sharing networks such as LimeWire, Kazaa and BitTorrent. They are also frequently spread as email attachments from senders masked as a friend. Always be wary of files with extensions of ".exe" on Windows or ".app" on Apple computers.

Removing Keyloggers

Most virus scanners will detect and remove keyloggers. Trend Micro HouseCall offers a free scanner that can be run through an Internet browser (see Resources). Other alternatives, such as Norton and McAfee Antivirus, can actively protect a computer to prevent keyloggers from ever being installed.

Warning

Even the best virus scanner can have flaws. Be careful, even if your computer is protected.