Modern Car Theft Methods Explained

Keyless Theft – How is it being done?

If your car comes with a smart key and push-to-start button it can be a super easy target for a professional car thief. Here I look at some of the modern methods used to compromise your vehicles factory security.

Remote Jamming/Blocking

Remote Blocking/Jamming leaves the car unlocked

This method involves transmitting a frequency that is in the same range as your cars remote control.  Quite simply, it blocks the signal and prevents the car from locking.

It does not require any sophisticated equipment and can be done with another car alarm remote! Ever press your remote and found it didn’t work? Then tried again and it did work!


Check to see if your car has actually locked or watch for the hazard lights to flash confirmation. If not you could be leaving your car open to content theft and a possible OBD-II Attack! (See below)

Don’t assume your car has locked because you hit the remote button!

Roll Jam Attack

This is an advanced version of Remote Jamming. It blocks the vehicle from receiving the code whilst recording it. The owner then presses the remote again and the first stolen remote code is used to lock the car. The second code is then stored to unlock the car in the future!

The video below explains the details. I’ve clipped it between 37.40 and 51.11 as it’s the most relevant part, but the whole thing is worth watching if you have the time.

Relay Amplification Attack

This method is used on vehicles that come with a smart key. It allows the thief to unlock and start your car by tricking it into thinking the smart key is in range.

KEYLESS BLOCK protects your car from Relay Attacks. More details here…


The following video covers Relay Attacks. Again I’ve cropped the video to the most relevant part which starts at 33.42 minutes in but again, the whole thing is worth watching:

OBD-II Remote Cloning

Programming a smart key via the OBD-II plug can be done in a couple of minutes with the right tools. The thief can then drive your car away!

Every car manufactured after 1996 has an OBD-II plug.

The “On Board Diagnostic” plug is there to help technicians read vehicle fault codes and electrical settings. It is also used by the Dealership and Automotive Locksmiths to code a new remote to the car using an OBDII scan tool.

These tools have become much more affordable in recent years and are easy to purchase.

An OBD BLOCK is an effective tidy way to prevent your OBDII connector from being hacked:

OBD BLOCK from Author

Traditional Remote Key V Smart Key

Remember any vehicle is easy to take if your keys get stolen, this remains the easiest way for a thief to take your vehicle.

Fact: Over 70% of cars are stolen with the keys!

A remote with a traditional key is much less vulnerable than a smart key for the following reasons:

  • It only transmits when the button is pressed so is not compromised by an Amplifier/Relay Attack.
  • The transponder immobiliser is not compromised by a Remote Blocking or a Roll Jam attack, but can still be vulnerable to an OBD-II key programmer.
  • It still requires a cut key, placed in the ignition barrel and turned, or for the steering lock to be broken and the vehicle to be hot-wired!

AUTHOR alarm has a great range of systems that protect against modern vehicle theft.

About Julian

Owner and Installer at Obsessive Vehicle Security Limited. More details here... Please keep Comments relevant to the post and use the Contact form for enquiry's
This entry was posted in Keyless Car Theft, Thieves, You really should know... and tagged . Bookmark the permalink.

2 Responses to Modern Car Theft Methods Explained

  1. Rich says:

    Is there anything you can do to prevent Amplifier/Relay Attack? Are the viper alarms able to be attacked via this method? I am guessing most if not all would be? Only reason I am asking as I am thinking about getting one installed.

  2. Julian says:

    Hi Rich,

    It would be good to know what vehicle you have so I can offer some advice.
    Cobra has the ADR card that protects against these attacks.
    I also have a CAN-BUS Immobiliser called IGLA which I will be putting up on the website in the next couple of weeks.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.