Hackers can destroy your computer with a USB drive. This isn’t an exaggeration or a hyperbole — a Russian security researcher designed a device that plugs into a normal USB socket that can overcharge a laptop or full size PC’s hardware and make it completely useless.

To top it off, a new study shows that people aren’t very picky about what they stick in their computer. A group of researchers from the University of Illinois, University of Michigan, and Google scattered 297 flash drives across a university campus and waited to see what happened. It took them six minutes before some hapless goon picked one up and stuck it their computer. Overall, the researchers estimated that the “attack” (as the flash drives could have been malicious) was successful anywhere from 45 to 98 percent of the time. That’s a pretty big margin of error, but it can only take one malicious drive to infect an entire network of computers — or just burn out their delicate circuit boards. The team usually attached the flash drives to a keychain or marked them with “confidential” stickers or other enticing tags, which is a common hacking technique. A hacker in Mr. Robot showed an identical exploit with a bogus CD disc — though a corrupted disc couldn’t light a computer on fire (that takes hardware concealed in the “drive”), it could just as easily plant a virus on your computer.

At the risk of sounding crass — plugging in a USB drive or anything else into your computer is a bit like having sex. You can catch all sorts of shit from doing it if you’re not safe. If you don’t know where a USB drive has been, don’t plug it into your computer. If you do, this might happen.

That’s Deep Purple, the Russian security researcher who first figured out how to make the USB computer-burners, trying out his “USB Killer 2.0” version that can brick a laptop computer in seconds.

Researchers polled the schmucks that could have blown up or infected their computers and found that most people were altruistic, popping in the potentially dangerous USBs to try to find their owners, but they still proceeded without a thought to their digital security.

It’s a pretty simple process — the USB drive is not a drive at all, but a system of Direct Current/Direct Current converters in a tiny box (Deep Purple goes into detail here). They charge up from the computer’s power and create a loop of voltage that’s way too much for the computer’s systems to handle and feed it back in. Presto, fried computer. Deep Purple ordered all the parts for his online and hand-soldered them together into a device small enough to fit inside the case of a normal-sized flash drive.

There is, however, a very simple way to protect yourself from this. If you see a random USB stick lying on the ground, don’t put it in your computer. If you plan on losing your own USB drives, put a label on them, so good samaritans can find you without sticking foreign objects in their delicate digital areas.