Which company develops one of the most widely used antivirus software products?

Symantec is recognized for developing one of the most widely used antivirus software products, specifically known for its Norton AntiVirus suite. The company has a long-standing reputation in the cybersecurity field, operating for decades to provide security solutions against viruses, malware, and other online threats. Norton products are popular among both individual users and businesses due to their comprehensive protection capabilities and proactive threat detection.

In contrast, while companies like Microsoft also provide antivirus solutions through Windows Defender, Symantec's Norton has historically been one of the market leaders, making it one of the most recognizable names in antivirus software. Similarly, US-CERT focuses on cyber safety and incident response rather than developing software, and Agnitum, while once known for its security solutions, is not as prominent in the industry as Symantec.