Both keystroke-logging software and hardware track the keystrokes on a keyboard and grab important information, including passwords and credit card numbers, all while the computer user is unaware. Usually it’s criminals trying to steal your information for financial gain, but this technology has also been used to catch employees who might be revealing company secrets over email and to spy on spouses suspected of cheating.

Most keystroke loggers (“keyloggers”) are software-based. But there are an increasing number of hardware-based tools that aren’t as easily detected as software. In most cases, the hardware is a small device attached somewhere between the keyboard and the computer -- usually near the USB or PS2 port, where it’s not easily visible.

Here’s how to keep yourself safe:

• Many premium security suites can detect software keyloggers, so be sure to use good antivirus and antispyware programs -- and keep them updated -- along with a personal firewall. Also, keep your Web browser software updated so it catches the new security vulnerabilities that are being found and addressed.

• Look into dedicated anti-keylogging products, such as KeyScrambler, which encrypts your keystrokes, and Anti-keylogger, which runs in the background and disables any keylogger programs detected.
• If you’re on a public computer, look at the keyboard, cable and back of the PC and report anything that looks suspicious.
• Limit any personal or financial information you’re typing on a public computer, just in case your keystrokes are being recorded.
• Never click on attachments or links that are embedded in an email or instant message, since that can increase your chances of having malicious software installed on your computer.

Here are two other tricks to try and fool keyloggers:

• Type in the first few letters of your email address or password, then click in a blank spot on the webpage you’re on and type in some random letters, numbers or symbols. Now go back and finish typing your email address or password.
• While some keyloggers can capture mouse movements or even take secret screen shots every few seconds, most simply record keyboard strokes. Therefore, you might consider pulling up your computer’s onscreen (“virtual”) keyboard and use that to type in login information and passwords.