The dongle, which the anonymous engineer has disguised as a thumb drive, cleverly circumvents the self-preservation mechanisms of USB ports by using a power converter and transistor. Normally, shorting the power and ground circuits of a USB together will trigger a built-in protection against static electricity, but the dongle’s transistor is able to transfer voltage from built-in capacitors to avoid shutoff.
It runs in a continuous loop, sending high levels of voltage down the USB port until, to quote the engineer, “everything possible is broken down.” The attack is particularly effective, HackADay notes, because USB is typically integrated with the processor in most modern laptops, putting it at risk of electrical overload.
The dongle was made purely as a proof of concept, so there isn’t much reason to panic yet. However, the relatively simple design makes it easy to duplicate. There’s always the chance some unscrupulous, enterprising soul will someday begin mass-manufacturing and selling it. Basically, don’t be surprised to see similar USBs appear on your crowdfunding platform of choice in the near future.