How it works
For years, owners of cars that use keyless technology have reported seeing their cars being effortlessly stolen by people walking up to them and driving away. Researchers at the German car club ADAC have now tested what is called the "amplification attack" on dozens of car models and found 24 of them vulnerable.
The hack involves tricking the car's radio equipment into thinking that the owner is near the vehicle with the keyless sensor. It involves boosting the signal in the key fob by making a couple of simple changes to the frequency in the car's radio equipment with an amplification device.
"The radio connection between keys and car can easily be extended over several hundred metres, regardles of whether the original key is, for example, at home or in the pocket of the owner," said the ADAC researchers.
The attack has been around for at least four years - Swiss researchers detailed a similar version of the hack back in 2011. But carmakers have not released a fix for the problem, and now German researchers have come up with an even cheaper and easier way to exploit it.
The ADAC researchers devised a system that can unlock and start the cars for just £160, where the Swiss researchers had spent thousands of pounds on their software.
They created two radio devices - an amplifier that must be positioned near the victim's key, and a receiver that should be placed near the car. The radio near the car impersonates the key and triggers the car to unlock.
The device can work from as far away as 90 metres.
The radios are simple to make, and the components cheap, according to the researchers. They have not released how exactly they made the devices, as they do not want to encourage potential thieves.
How can I protect my car?
There is no simple fix for the hack, unfortunately. If you own a car that uses keyless technology - or one of the models below - you could try storing your key in a "faraday cage", designed to block radio signals, or a freezer, as one New York Times journalist did.
Really, it's down to car manufacturers to build defences into wireless key fobs.
Models that can be hacked
- Audi: A3, A4, A6
- BMW: 730d
- Citroen: DS4 CrossBack
- Ford: Galaxy, Eco-Sport
- Honda: HR-V
- Hyundai: Santa Fe CRDi
- Kia: Optima
- Lexus: RX 450h
- Mazda: CX-5
- Mini: Clubman
- Mistubishi: Outlander
- Nissan: Qashqai, Leaf
- Opel: Ampera
- Range Rover: Evoque
- Renault: Traffic
- Ssangyong: Tivoli XDi
- Subaru: Levorg
- Toyota: Rav4
- Volkswagen: Golf GTD, Touran 5T