Malware is the overal name for harmfull things like trojans, virusses, spyware, addware and things like that. Avast sure is capable to detect and handle them. In fact, avast has been recently chosen as best antivirus by customers in the USA and Europe!
It sounds more like you have a couple of things to learn about security (no offense ment), and therefor I kindly ask you to visit my website
www.ache.nl and read how to clean and protect a system.