BadUSB is a computer security attack using USB devices that are programmed with malicious software. For example, USB flash drives can contain a programmable Intel 8051 microcontroller, which can be reprogrammed, turning a USB flash drive into a malicious device. This attack works by programming the fake USB flash drive to emulate a keyboard, which once plugged into a computer, is automatically recognized and allowed to interact with the computer, and can then initiate a series of keystrokes which open a command window and issue commands to download malware.
The BadUSB attack was first revealed during a Black Hat talk in 2014 by Karsten Nohl, Sascha Krißler and Jakob Lell. Two months after the talk, other researchers published code that can be used to exploit the vulnerability. In 2017, version 1.0 of the USG dongle, which acts like a hardware firewall, was released, which is designed to prevent BadUSB style attacks.

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