I think this is about detecting such behaviour?
Keyloggers usually use some very specific API calls that makes it easy to detect them, and that route, OpenSBI can easily detect them as a file.
OpenSBI can currently only react to files (and other stuff on disk or accessible by various system APIs), meaning to the source and outcomes of behaviour. Which is usually faster and less intrusive on the whole system.
Monitoring the behaviour itself would be something very live protection related. Spybot 2.0 and 2.1 can /will be able to monitor more in the regard.
Our current RootAlyzer reacts to behaviours as well (e.g. hiding files, a standard rootkit action), but is not user-extensible right now.