Tuesday, July 29, 2014
A keylogger, sometimes called a
keystroke logger, key logger, or system monitor, is a hardware device or small
program that monitors each keystroke a user types on a specific computer's
keyboard. As a hardware device, a keylogger is a small battery-sized plug that
serves as a connector between the user's keyboard and computer. Because the
device resembles an ordinary keyboard plug, it is relatively easy for someone
who wants to monitor a user's behavior to physically hide such a device
"in plain sight." (It also helps that most workstation keyboards plug
into the back of the computer.) As the user types, the device collects each
keystroke and saves it as text in its own miniature hard drive. At a later
point in time, the person who installed the keylogger must return and
physically remove the device in order to access the information the device has
gathered.
A keylogger program does not
require physical access to the user's computer. It can be downloaded on purpose
by someone who wants to monitor activity on a particular computer or it can be
downloaded unwittingly as spyware and executed as part of a rootkit or remote
administration (RAT) Trojan horse. A keylogger program typically consists of
two files that get installed in the same directory: a dynamic link library
(DLL) file (which does all the recording) and an executable file (.EXE) that
installs the DLL file and triggers it to work. The keylogger program records
each keystroke the user types and uploads the information over the Internet
periodically to whoever installed the program.
Although keylogger programs are
promoted for benign purposes like allowing parents to monitor their children's
whereabouts on the Internet, most privacy advocates agree that the potential
for abuse is so great that legislation should be enacted to clearly make the
unauthorized use of keyloggers a criminal offense.
