As if stories if malware infiltration via USB were not enough, an electronics engineer has designed an innocuous looking thumb drive which can completely fry your laptop, writes Kyle Wiggers for Digital Trends.

Unfamiliar USB Flash Drive? It Could Fry Your Laptop

Bypassing USB safety features

The dongle looks innocent enough, and unsuspecting computer users may not think twice before plugging it into their machine to see what exactly it contains. In the case of this recently released prototype, curiosity could indeed kill the cat, or at least its laptop.

The anonymous engineer built a device which bypasses the self-preservation mechanisms of USB ports using a power converter and transistor. Under normal conditions shorting the power and ground circuits of a USB at the same time will cause built-in protection against static electricity to kick in, but the dongle uses a transistor to transfer voltage from built-in capacitors to prevent the port from shutting down.

Consequently a continuous loop of high voltage enters the computer via the USB port until “everything possible is broken down,” according to the engineer. This method of attack is highly effective against most modern laptops, whose USB is usually integrated with the processor, leaving it vulnerable to electrical overload.

Not for sale… yet

The engineer claims that he only made the device to prove a concept that he came up with after hearing a story about a man stealing a USB stick on the subway, which later fried his laptop when he plugged it in. That is not to say that an unscrupulous entrepreneur could not begin manufacturing and selling the device, given that its simple design would be easy to replicate.

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.