Anti-spyware built-in

Spyware is software installed on a computer that is designed to collect information about the computer user, often without their knowledge or consent. This can result in so called identity theft, or theft of valuable information (e.g. bank or credit card details) or proprietary business data. Spyware is often developed by organized crime rings rather than lone individuals and may be installed by a virus.

Certified by West Coast Lab's Checkmark process, avast! has full anti-spyware capabilities built-in, to make your protection even more complete.
Anti-rootkit built-in

Rootkits are programs that install on your computer while keeping themselves and their activities hidden to remain invisible to the use. They represent a significant security risk on both home computers and company networks and are notoriously difficult to find and remove. Rootkits themselves are normally installed by a virus or other type of malware infection and it is therefore highly recommended that computer users have up to date antivirus/anti-spyware software installed and running on their computer. One such system is avast! antivirus