Software used to protect computers from malware includes antivirus programs, anti-spyware, and firewalls. They work by detecting, preventing, and removing harmful software that can compromise a computer's functionality or steal personal information. Popular examples include Norton, McAfee, and Bitdefender. These solutions use various techniques such as real-time scanning, heuristic analysis, and behavioral monitoring to enhance security. Regular updates are also essential to ensure they can combat new and evolving threats effectively.