Like many antivirus programs, it can run a full or custom scan to check the computer for malware in order to remove them. It updates its virus definitions automatically everyday by default using the Internet. Contains popups-ads. Avira Free Antivirus is our flagship product, trusted by millions of users around the world. While our system scanner protects you from all types of malware, our complementary toolbar safeguards your privacy and includes a reputation advisor, which rates the security of websites in your search results.