Hackers can take control sniper rifles and make them fire at another target.

“Smart guns”, which have a computer mounted on them to make them fire more accurately, are surging in popularity. But hackers have shown how they can take control of those gun-mounted computers and disable the computer or change the gun’s target.

Security researchers Runa Sandvik and Michael Auger will demonstrate the techniques at the Black Hat hacker conference, reports Wired. They involve taking control over the gun using its wifi connection and exploiting weaknesses in the software that it runs.

The rifles can cost up to $13,000, and can turn an “amateur shooter into a world-class marksman”, reports Wired. They work by letting users choose a target and add in things that would normally throw off a shot — temperature and the kind of ammunition — accounting for them so that people can tell exactly where they need to shoot.

But the hacks can completely disable the computer, making the thousands of dollars spent on the computer worthless. As well as changing the direction of the gun by tricking it into altering the scope, a hacker could lock down the computer and delete its files so that it becomes useless.

Despite being able to change the direction of the shot, hackers don’t seem to be able to actually force a gun to shoot. The TrackingPoint rifles are made so that the guns will only fire if the hardware trigger is actually pulled.