Value for each delta will vary, but every extra step (the need to install a keylogger) or dependency requirement (that this be an interactive node and someone eventually logs in) will decrease your overall chance of penetration.
Almost no one has the resources to stand up to a targeted attack from even a mildly capable hacker. Therefore, the risk profile most administrators are working against are attacks of opportunity. In that race, as in the old joke about outrunning your friend instead of a lion, you need only be be some small amount more difficult to crack than the next potential victim.
Almost no one has the resources to stand up to a targeted attack from even a mildly capable hacker. Therefore, the risk profile most administrators are working against are attacks of opportunity. In that race, as in the old joke about outrunning your friend instead of a lion, you need only be be some small amount more difficult to crack than the next potential victim.