Keyloggers are one of the fastest-growing and most concerning threats on the Internet today. Keyloggers are a bit worrisome because they were first written as legitimate programs, designed to monitor and catalog the use of the keyboard, and they continue to masquerade as harmless programs. Because of this, many antivirus or anti-spyware programs only report them as ?potentially? dangerous or do not recognize them at all. The true danger also lies in their ability to not only catalog information, but to relay it to other machines without your knowledge.

The term ?keystroke logger? or ?keylogger? comes from the early days of computing, before the advent of the mouse or modern, high-resolution graphics. At that time, all information entered into and used by a computer system was entered via the keyboard. A keylogger keeps an actual record, or log, of each key as it is pressed. They were first developed for admirable uses: to monitor and measure employee productivity on clerical tasks, as corporate security and parental controls and sometimes as law enforcement tools. Even the FBI reportedly used a keylogger program to help catch convicted mobster Nicodemo ?Little Nicky? Scarfo in 1999.

Since then, these once innocuous programs have been altered by some programmers to not only log keystrokes, but to transmit the information gathered via the Internet to other machines. They gather these keystrokes in order to capture passwords, account numbers, personal identification numbers and credit card numbers for use in frauds and scams. The potential for problems ranges from the installation of simple advertising software to stolen personal information.

Keyloggers can invade your PC in two forms: hardware and software. The hardware method uses a physical device that can either be attached to the keyboard, installed inside the keyboard or replace your existing keyboard altogether. The information logged must be retrieved manually from the device. An external device or a replaced keyboard would be fairly obvious, even to the most novice computer user, but the devices installed within the keyboard are virtually undetectable by the average user. However, unless you have given unscrupulous technicians or users access to your computer, this won't likely be a problem on a home system. Hardware keylogging is more of an issue for those who use public computers, like in internet cafes or public libraries. Even so, you should still be very careful of who you let fix or use your home computer.

Software, on the other hand, is much easier to slip onto home PCs. The methods of installation are the same as those used by other viruses or malicious software (known as ?malware?). Attachments in unsolicited e-mails, banner and pop-up ads and freebies are the most common culprits. The real trouble with these programs lies in the fact that since they were -- and still are -- being used for valid reasons. In addition, they don't interfere with any one program in particular but instead target the entire operating system. For these reasons, many antivirus and anti-spyware programs either don't acknowledge keyloggers as a problem or minimize the danger by labeling them as merely ?potentially? unwanted programs.

Even though these programs are hard to detect, they are not completely invulnerable to detection and removal. The problem with transmitting information out of your system is that it leaves an electronic trail. There are specific anti-keylogger programs which can detect these trails now. Since use of these programs is on the rise, many experts expect more to be developed. In addition, some of the more current and updated antivirus programs are beginning to include keyloggers in their databases. However, you may still need to adjust the program's default settings to a higher level of protection and you will need to maintain a subscription to keep your PC's protection up to date. A firewall may not prevent the information you are typing from being cataloged, but it can prevent that data from being transmitted out of your computer. Network monitors (also called reverse firewalls) won't tell you if a program is coming into your computer, but they will notify you if a program is attempting to open an internet connection of its own or transmit data.

The best protection from any kind of problem program, including keyloggers, is an educated and aware computer user. It's best not to use public computers for banking, paying bills or other activities where your password may be at risk. Banner ads and pop-up ads can be very tempting but they are the primary method these scammers use to install malicious software on your computer. Avoid clicking on them at all, even just out of curiosity. Free programs are also internet temptations. Many are harmless in their own right, but they allow malware to ride piggyback on their installation. You should install only what you need and only from sites you know and trust. You should also only hire technicians with references and proven track records. If you take some of these basics steps to protect your PC, you really can minimize your exposure to the growing threat posed by keyloggers.