Page "Keystroke logging" Paragraph 45

However, the particular technique that the anti-spyware application uses will influence its potential effectiveness against software keyloggers.

As a general rule, anti-spyware applications with higher privileges will defeat keyloggers with lower privileges.

For example, a hook-based anti-spyware application cannot defeat a kernel-based keylogger ( as the keylogger will receive the keystroke messages before the anti-spyware application ), but it could potentially defeat hook-and API-based keyloggers.