Keylogging, also known as key logging or key stroke logging, is the use of a device (hardware) or program (software) that possesses the ability to record each key stoke made on a computer. Everything can be tracked, including: emails, instant messages, documents, spreadsheet entries and most importantly, account numbers, PINs, login names and passwords. If the keylogger is a software program, after the information is gathered, the keylogger creates a log file and sends it to a specified recipient. In the case of keylogger hardware, the person who installed the hardware must retrieve the device in order to access the information gathered.

Types of Keyloggers
As a commercially available hardware device, the keylogger comes in several forms. It can be a connector between the computer and the end of the keyboard plug that looks to most users like it is supposed to be there. Some can easily be installed inside a standard keyboard. There are also replacement keyboards available with the keylogger already built in.

As software, a keylogger can be purposefully downloaded or installed unbeknownst to the user via a virus or spyware, which is then executed using a trojan horse or other means. The program can also be inserted into an email that directs the user to respond or click on an attachment and enter personal information. Keyloggers also sit on various websites waiting to install themselves on unpatched or unsecured machines that hit their site.

Keylogging does have constructive purposes including software development. The examination of the keystrokes will indicate any errors, which the developer can then easily correct. Some employers use keylogging to determine the productivity of employees, or to ensure that they only use work computers for business purposes. Law enforcement officials may use keyloggers to circumvent applied security measures and obtain passwords or encryption keys. Concerned parents might use the tool to monitor their children’s online activity.  Despite the constructive uses for keylogging the related concerns are legitimate due the possibility of theft.  Malicious keyloggers strive to uncover usernames, passwords, PINs or other information necessary to gain access to financial accounts.