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A redditor posed an intriguing question to the /r/Autos forum: Their car had been stolen, then turned up a few streets away. Was it in danger of being stolen again? The resounding answer was that yes, thanks to a clever new technique the thieves had their own set of car keys. What’s more, it had been abandoned as part of an especially ingenious strategy.

The car–a 2021 Hyundai Ioniq hybrid–had been stolen using a “relay attack.” This is a popular tactic for cars equipped with keyless entry and engine start. One thief holds a wireless “relay” device by your front door. This extends the signal of any key fobs nearby. Another thief waits near the car with a signal repeater. Then they simply open the car and start the engine.

So how in the world do they get their own set of keys. They also come prepared with a blank manufacturer key and a computer to plug into the vehicle’s OBD port. Once zinside, they can program the blank key fob to that car and get full control.

Two thieves drive off in highjacked car
Car thieves | bluegame via iStockPhoto

The redditor with the 2021 Ioniq was already aware of the danger of a relay attack. This is why they normally keep their key fob in an RFID-blocking pouch so thieves can’t repeat its signal. But on that unfortunate night, they forgot and left the keys lying around their house. But they weren’t fully aware that thieves can now program a new key, so they asked the internet if their car could be stolen again.

Multiple commenters urged the driver to go to a dealership or locksmith and have the car “re-keyed” as soon as possible. During this procedure, all existing key fobs would be deleted from the car’s system so the thieves couldn’t snag it again. A more aggressive intervention would be to have an aftermarket kill switch installed–such as those made by LoJack–that they could then trigger remotely.

The biggest mystery is why the thieves ditched the car a few streets away. This is a relatively common practice, since the advent of aftermarket vehicle trackers. If thieves don’t want to give away the location of their home base, they will park a car in some random spot and wait to see if the owner retrieves it. If it is still there in a few days, they assume the owner has no way to track it and it’s safe for them to drive home.

Next, find out exactly how to wrap your keys in aluminum foil to stop a relay attack, or see more ways to defend your car from thieves in the video below:

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Staff Writer

Henry Cesari

Henry Cesari joined MotorBiscuit in 2021 and brings his deep interest in vintage cars, trucks, and motorcycles to the site. Having restored his first classic car at just 16 years old, Henry has wrenched on everything from overland campers to Japanese motorcycles and even pre-war Bugattis. Henry is also an avid attendee at local car shows and genuinely enjoys connecting with fellow auto enthusiasts.

Henry earned a Bachelor’s in Anthropology and English from the University of Vermont. He has since incorporated his love of the written word with his admiration of classic cars. While Henry is interested in vintage cars, he believes the golden age of cars is yet to come. He is confident journalists will play an important role in this revolution by exposing the industry as it is now and envisioning its possible future.