How Does Antivirus Work?
Antivirus is software that identifies, isolates, and deletes malware (malicious code) on computers. It also scans and rescans files, folders, and external devices to detect infections and prevent malware from spreading. Antivirus is a vital layer of cybersecurity for both consumers and businesses. It can be paired with other tools to provide comprehensive protection, such as firewalls and endpoint detection and response (EDR) solutions.
Antivirus works by comparing the signatures of known malware with those stored in its database. It can also use behavior-based detection, which looks for suspicious patterns in a program’s actions to identify threats that are not yet part of the signature database.
Viruses, Trojans, and Worms
While it’s still possible for people to get viruses on their home PCs, the threat landscape has dramatically changed since Josh Brunty, a West Virginia digital forensics analyst and security professor, began paying money each year for third-party antivirus software on his personal systems. Now, most experts agree that the antivirus included in the free Windows operating system—and now also on most mobile devices—is just as good as or better than the third-party alternatives, and it can be updated automatically.
Most modern AV solutions have also evolved beyond traditional signature-based analysis to offer heuristic analysis, which is designed to catch as-yet unknown or altered versions of existing malware. These methods can also help to avoid false positives, where a legitimate program or file is flagged as malicious.