- Avast! is based on a central scanning engine that is certified by ICSA Labs
- Priority updates are delivered automatically using PUSH update technology in Avast! Pro Antivirus. Avast! Pro Antivirus also has a command line scanner and a script blocker.
- File System Shield — Real-time protection against viruses and other malware threats. Scans files as they run on your computer to keep viruses from being able to execute.
- Mail Shield — Scans messages and attachments in E-mail/Microsoft Outlook/Exchange for viruses.
- Web Shield — HTTP protection (local transparent proxy). Version 4.8 also allows the blocking of URLs. Scans URLs and incoming data for viruses, and aborts connections to the site if one is found.
- Avast! antivirus was awarded the "Advanced" rating by AV Comparatives
- Avast! antivirus was awarded the "Advanced+" rating by AV Comparatives