http://www.avast.com/eng/avast-4-home_pro-...on-history.html
-avast! now contains a built-in anti-rootkit protection
-avast! now comes with a built-in anti-spyware protection
-new self-defense function to prevent active malware from terminating avast! processes as well as corrupting avast! files and registry items
Way to go Avast!
Edit: Found this message by Avast forum moderator, concerning anti-rootkit and spyware protection:
Yes, those features are integrated into the ordinary scan... so there are no special options (well, you can create a new anti-rootkit task in the Enhanced User Interface, if you have the Professional version, but basically you can say that avast! protects you against spyware and rootkits automatically).