Ask Arthur

How was my alarm cloned?

A reader asks: What can we do if we suspect the remote alarm for our car and home has been cloned? It’s a 2014 Mercedes-Benz C200. Important items have disappeared from my car and home.

Firstly, you need to be aware of how it may have happened, to prevent a recurrence, and to warn others. There are several ways it could have happened.

Radio Frequency (RF) scanning, known as “signal sniffing”: Criminals use a RF scanning device to capture the radio signal emitted by your key fob when you lock or unlock the car, and thus capture the code sent by your key fob.

This is more common with older fixed-code fobs, which transmit the same code every time, which is why a 2014 model car may have been vulnerable.

Signal amplification: Key fobs that are automatically detected by a car when it is in close proximity can be targeted by signal amplification devices to extend the range of the signal, so that it opens the car even while you are inside a house or office.

Hacking the car’s systems: Sophisticated thieves might also exploit vulnerabilities in the car’s electronic systems to gain access.

In 2022, researchers identified vulnerabilities in the telematics systems of multiple brands. Researchers tend to work with manufacturers to address such vulnerabilities before they can be exploited.

What can you do?

Contact the manufacturer or dealer as first priority. In our reader’s case, however, Mercedes was unable to help with the reprogramming. That is the second priority:

Reprogramme or replace the key fob: If the dealer couldn’t help you, find a certified automotive locksmith.

Try additional security measures: Install an aftermarket alarm system or a signal-blocking pouch.

Update vehicle software: Manufacturers’ updates sometimes address security vulnerabilities.

Rolling code key fob: It generates a unique code each time you use it, making it more difficult to clone.

Some say criminals can block and “record” that specific code, and “replay” it to get access to the car. But that requires both sophisticated criminals and specific circumstances so is highly unlikely.

Use physical security: A steering wheel lock is a serious deterrent these days, as criminals don’t expect it.