Antivirus  software (often abbreviated as AV) is computer software used to prevent, detect and remove malicious software. We recommend AV software for all computers connected to the Internet, and depending on your environment, perhaps even ones that are not- viruses can even be spread by other means like unwittingly plugging an infected USB drive into a computer.  Because virus makers are evolving ever new techniques no antivirus software is 100% effective, so it is recommended to be part of a more holistic approach which could include utilizing multiple scanning engines, web filters, and perimeter security devices such as a UTM firewall to catch malicious programs before they infect your business.