“BadUSB, can be installed on a USB device to completely take over a PC, invisibly alter files installed from the memory stick, or even redirect the user’s internet traffic.”  The Wired report went to say:

The problem isn’t limited to thumb drives. All manner of USB devices from keyboards and mice to smartphones have firmware that can be reprogrammed—in addition to USB memory sticks,…

The malware can silently hijack internet traffic too, changing a computer’s DNS settings to siphon traffic to any servers it pleases. Or if the code is planted on a phone or another device with an internet connection, it can act as a man-in-the-middle, secretly spying on communications as it relays them from the victim’s machine.

In a time of cyberintrusions every day people should not be ignoring the USB devices that surround us!