Gradually, the system's files will get affected and your system will start behaving oddly. Some viruses and malicious files transfer through USB flash drives to a PC system. Question 2: How Do You Make Sure Your USB Is Safe? Or you can use a reliable antivirus tool to scan the USB flash drive first. Try to avoid using such flash drives from third-party users. So whenever you use an infected USB drive to a different system, the system will get automatically infected. Some viruses only transfer through USB drives. Yes, USB drives carry viruses and can infect multiple systems. Before you start to scan virus on you PC, you need to understand two things about the USB Virus. This is why you need a USB Virus Scanner tool. The system will not turn up because of the virus attack. Hence, there comes a time when the infected USB drive crashes the entire system. However, what many people don't know is that, when you plug the USB drive into an infected system, the virus will come along and infect other PCs. But one important usage is to store precious data or songs or videos. Maybe you all use USB devices to connect with the computer system, as they are very helpful to transfer data from one PC to another. Bonus: Recover Your Data After USB Get Infected.10 Best USB Virus Scanners for You to Try.