Usually key loggers can record the application name, date and time of execution and keystrokes associated with that application. They can capture keystrokes even before they get encrypted; this gives the attacker password and other hidden information easily.
-Software Key loggers
-Hardware Key loggers
Software Key loggers:
Software key loggers are widely used since they can be installed remotely via network or email attachments. Software key loggers always have ability to obtain additional data since they are not physically limited and can access memory allocations. The best part offered by software key loggers is that they can be deployed with any Virus or Trojan program that means you can use a Trojan as software key logger. They need administrative privileges to install on system.
Practically you should not trust any illegitimate program. Keep your Anti-Virus program and firewall updated. Download Mozilla fire fox and use Key-scrambler plug-in to avoid keystroke getting monitored on web browser if someone has successfully installed a key logger in your system. If you are doubtful that your system has been infected by key logger use anti-key-logger/key-logger-remover programs to get rid of them. Following is list of some Anti-Key logger programs.
Advanced Anti-Key logger
Spy Hunter-Spyware Remover
If you are wondering what anti-spy ware is doing in list of anti-key logger then I must tell you that key loggers are part of spy wares (also key loggers can be classified under spy ware) and hence even spy ware removers are capable of removing key loggers.
Counter Measure against Hardware Key logger:
At practical level there’s hardly any software based counter measure to hardware key loggers. But here’s a program that can protect against both hardware and software key loggers. Its name is Privacy Keyboard.
Privacy Keyboard is anti-spy ware that defends computers from both spy software and hardware. It can detect software key loggers and can also helps in evading hardware key loggers though it can’t detect them. It disables all spy softwares running on the system and prevents hardware as well as software key loggers from intercepting keystrokes.