PCI DSS requires the deployment of antivirus on all systems typically infected by malware, such as Windows operating computers. Anti-virus software often offers every system inside a network an extra layer of protection.
Malicious software, commonly referred to as "malware" including worms, viruses and trojans, reaches the network during a number of business-approved activities, including employee email and Internet usage, mobile phones, and storage devices, resulting in system vulnerabilities being exploited.