The premium Avast software adds several features. If it can't stop the malware before, it interrupts the downloading process. Avast detects most forms of malware before they reach your computer by quarantining and deleting the files. Features such as an email scanner, a secure browser and a URL screener are all available for free as separate tools.Īs for the antivirus and malware scanning itself, independent lab tests give it a high rating. Its basic scan also finds network issues, out-of-date software, weak passwords, malicious browser add-ons and more. The free program offers malware protection, a performance scanner and a scan scheduler.