“It’s often overlooked, but your company’s physical premises can expose it to cyber attack. During working hours, or after hours for that matter, without proper security measures in place, a hacker could conceivably walk right into your building, office, or cubicle and plug an infected thumb drive into the first computer he or she sees. Therefore, you need to make sure your properties, key partners and, ideally, your entire supply chain are physically secure.
Besides keycard building entry, improving physical security requires you to manage visitor, contractor, and employee access throughout your facility and sensitive areas, and what they have access to. It may involve controlling physical access to network rooms and equipment, security tokens for computer access, and implementing both timed lockout and password protection of network devices. And it certainly entails employee security awareness training.”
Source: Cyber risks threaten physical security, industrial controls.