USB
As you may already know, USB drives can infect computers with malware or other malicious software. Many liken the situation to reusing a contaminated needle. At present there aren’t many tools that address this potential entry point for hackers, so it is wise to be cautious with USB drives and what is stored on them as well as what machines they are plugged into.

But the situation may be even worse since so many peripherals utilize USB cards to interface with computers. Security Research Labs out of Germany speculates that these devices might be used to hack computers.

 

You can read the IEEE Spectrum write-up here.