A USB Killer is USB drive that has been modified to deliver an electrical surge that can damage or destroy hardware when the altered thumb drive is inserted into a computer's USB port.The modified drive essentially commands the computer's on-board capacitors to rapidly charge and discharge repeatedly. If left alone, the repeated overcharging will overload the USB port and physically destroy the computer's electrical system.
Essentially, a USB Killer works by delivering 210-220 volts to an interface that is designed for 5 volts. The overpowered-surge can damage or destroy not only ports, but also attached hardware. The concept behind USB Killer is similar to that of Ethernet Killer, a modified power cord that does much the same thing.
USB Killer is sold commercially under the name USB Kill. The original concept behind the device was allegedly to help hardware manufacturers and network administrators determine how well a digital device could withstand power surges and electrostatic discharge (ESD). Since its invention, however, this type of altered thumb drive has not been used for penetration testing by any major company -- it has proved popular with cybercriminals, however.
The concept of a USB Killer is credited to a Russian computer researcher known as Dark purple. In the United States, USB Killer was infamously used in the wild by a student at the College of Saint Rose in upstate New York. The student, who used his iPhone to record himself using USB Killer, destroyed over 60 college computers and was sentenced in 2019 to one year in federal prison.
To avoid being harmed by a rogue USB Killer, security experts recommend that network administrators and end users take the following steps:
- Apply firmware updates as soon as they become available.
- Refrain from using USB drives of unknown origin.
- Cap USB ports on mission-critical devices.