Keylogging is a method of capturing and recording user keystrokes. Keylogging can be useful to determine sources of errors in computer systems, to study how users interact and access with systems, and is sometimes used to measure employee productivity etc. But this can also be used to obtain usernames, passwords and even credit card numbers illegaly. Keyloggers are very useful for the law enforcem,ent agencies also to capture some data that leads to some conclusions in their investigations. Keyloggers are widely available on the Internet for downloading.
There are two types of keyloggers, Software as well as Hardware. We can see both of them and their working in the following paragraphs
Hardware key loggers are commercially available devices which come in three types:
1. Inline devices that are attached to the keyboard cable
2. Devices which can be installed inside standard keyboards, and
3. Actual replacement keyboards that contain the key logger already built-in.
When used covertly, inline devices are easily detected by a glance at the keyboard connector plugged into the computer.
Local Machine software Keyloggers are keyloggers installed directly on to the target computer
Remote Access software Keyloggers are local software keyloggers programmed with an added feature to transmit recorded data out of the target computer and make the data available to the monitor at a remote location through data is uploaded to a website or an ftp account, or periodical e-mail or through the LAN.
Detecting these key loggers are very difficult and most of the anti virus software and Spywares doesn't even recognize them. While you are working with a public access computer system like a cyber cafe, do not use your credit/debit card information to make online purchases. Some key loggers even didn't appear in the installed programs list or even a shortcut in the desktop or listed in the programs listing.