Mastering Car Hacking with Kayak: A Practical Guide for Beginners

Car hacking, often perceived as a purely malicious activity, holds significant potential for ethical exploration, security research, and even vehicle enhancement. Within this domain, tools like the Kayak car hacking tool are invaluable for understanding and interacting with vehicle networks. This guide will delve into how to effectively use the Kayak tool, providing a practical pathway for enthusiasts and professionals alike to explore the intricacies of automotive cybersecurity.

While this article focuses on Kayak, it’s crucial to acknowledge that car hacking encompasses a wide array of techniques and potential vulnerabilities. This guide aims to provide a foundational understanding and hands-on experience, but it’s not exhaustive. Remember, ethical considerations and legal boundaries are paramount when engaging in any form of vehicle hacking.

It is also essential to understand that the information presented here is for educational purposes only. The author and carscannertool.store assume no liability for any misuse or adverse outcomes resulting from attempting the techniques described in this article. If you choose to experiment with car hacking, especially on a physical vehicle, proceed with extreme caution and at your own risk. Fortunately, this guide will primarily focus on a virtual environment, offering a safe space to learn and practice.

Let’s begin by understanding the fundamental communication network within a vehicle that makes car hacking possible: the CAN bus.

Understanding the CAN Bus in Modern Vehicles

The Controller Area Network (CAN bus) serves as the central nervous system of a modern vehicle, facilitating communication between its numerous electronic components. Imagine a network where various parts of your car – from door locks and speedometer to brakes and engine controls – all communicate using electrical signals. This is the CAN bus in action.

Think of the sheer number of functions in your car that rely on electronic signals. Operating your windows, checking your fuel level, activating your anti-lock braking system (ABS), or even adjusting your mirrors – all these actions involve signals transmitted across the CAN bus. It’s the backbone for real-time data exchange within your vehicle.

OBD-II Port: Your Gateway to the CAN Bus

The On-Board Diagnostics II (OBD-II) port is a standardized interface in your vehicle that provides access to diagnostic information and, crucially, to the CAN bus network. Mechanics routinely use this port to connect diagnostic scanners, retrieve error codes, and assess vehicle health. This accessibility also makes it a key entry point for car hacking.

Locating the OBD-II port is usually straightforward. It’s typically situated within the passenger compartment, often under the dashboard on the driver’s side near the pedals, beneath the steering column, or sometimes on the passenger side. Here’s a visual representation of an OBD-II port:

An example of a vehicle’s OBD-II port, commonly used for diagnostics and accessing the CAN bus network.

To physically interface with the OBD-II port, you would typically use a device like the CANtact tool. While physical connections are beyond the scope of this article, the virtual hacking techniques we’ll explore using Kayak are applicable whether you’re working with a physical vehicle or a virtual simulator. The OBD-II port remains the logical access point for CAN bus communication in both scenarios.

CAN Bus Communication: Hub-Like Broadcasting

The CAN bus network operates somewhat like a network hub in older computer networks. Data packets transmitted on the CAN bus are broadcast to all connected devices. Unlike a network switch that directs data only to the intended recipient, a hub (and the CAN bus in this analogy) makes data visible to every device on the network.

This broadcasting nature means that when you perform an action in your car, like locking the doors, a signal is sent across the CAN bus and “heard” by all electronic control units (ECUs). Each ECU then determines if the message is relevant to its function. For example, when a “lock doors” command is broadcast, the door lock ECUs recognize and execute the command.

Consider the door lock example further. When you press the lock button, an electrical signal is generated and transmitted as a data packet on the CAN bus. This packet contains instructions, such as “lock” or “unlock.” The door lock mechanisms, constantly monitoring the CAN bus, receive this packet and act accordingly, locking or unlocking the doors.

Many vehicle functions operate on this principle: an action initiates a data packet transmission on the CAN bus, and the relevant ECU responds to the instructions within the packet. Pressing the accelerator pedal, for instance, sends data packets instructing the engine control unit to increase fuel flow, leading to acceleration. This, in turn, might trigger the speedometer ECU to update the displayed speed based on the network instructions.

CAN bus packets are structured into two main components: the identifier and the data field. The identifier acts as an address, indicating which device or function the packet is intended for. The data field contains the actual instructions or information for that device.

For instance, a CAN packet might look like this:

120#F289632003200320

Here, “120” represents the identifier, and “F289632003200320” is the data field. It’s crucial to understand that CAN identifiers are not universally standardized across all vehicle makes and models. An identifier like “120” might correspond to the accelerator pedal in a 2019 Honda Civic, but it could control the windows in a 2022 Toyota Sienna. Identifier mappings are generally consistent only within vehicles of the same year, make, and model.

Finally, CAN bus networks are continuously active whenever the vehicle has power, even when the engine is off. This constant communication flow is essential for various background operations and readiness for driver commands.

The Replay Attack: Understanding the Hack

The car hacking technique we’ll focus on is a replay attack on the CAN bus. This method involves intercepting and recording CAN bus packets during normal vehicle operation and then “replaying” these packets back onto the network later to trigger the same actions.

Imagine recording the CAN bus traffic when you unlock your car doors using the remote. A replay attack would involve sending those exact recorded packets back to the car at a later time. If successful, the car doors would unlock again, even without pressing the remote. This demonstrates how recorded CAN bus commands can be re-injected to manipulate vehicle functions.

Before we dive into the practical steps, let’s set up the necessary software tools in a virtual environment to safely practice this replay attack.

Setting Up Your Virtual Car Hacking Toolkit

We’ll be using a fresh installation of Kali Linux 2022.2 within VirtualBox for this tutorial. It’s assumed you have VirtualBox and Kali Linux already installed. We’ll be installing three key tools:

ICSim (Instrument Cluster Simulator): A virtual car simulator to visualize our hacking efforts.
Socketcand: A daemon to bridge CAN traffic to network sockets.
Kayak: Our primary car hacking tool for analyzing and replaying CAN bus data.

First, update your Kali system and install prerequisite packages:

sudo apt update && sudo apt install libsdl2-dev libsdl2-image-dev can-utils maven autoconf

Create a working directory named “Car_Hacking” in your Documents folder and navigate into it:

mkdir Documents/Car_Hacking && cd Documents/Car_Hacking

Clone the ICSim Git repository:

git clone https://github.com/zombieCraig/ICSim.git

Navigate into the ICSim directory and compile the simulator:

cd ICSim && sudo make

Move back to the “Car_Hacking” directory and clone the socketcand repository:

cd .. && git clone https://github.com/linux-can/socketcand.git

Enter the socketcand directory and download a missing configuration file:

cd socketcand && wget https://raw.githubusercontent.com/dschanoeh/socketcand/master/config.h.in

Configure, compile, and install socketcand:

autoconf && ./configure && make clean && make && sudo make install

Finally, return to the “Car_Hacking” directory and clone the Kayak Git repository:

cd .. && git clone https://github.com/dschanoeh/Kayak.git

Navigate into the Kayak directory and install it using Maven:

cd Kayak && mvn clean package

With these steps completed, your virtual car hacking toolkit is ready, and we can proceed to execute the replay attack using Kayak.

Executing the CAN Bus Replay Attack with Kayak

For this practical demonstration, we’ll need to use multiple terminal windows simultaneously, each dedicated to a specific function:

Simulator: Running the ICSim virtual car environment.
Controls: Operating the virtual car’s controls.
Capture/Replay: Using Kayak and can-utils to capture and replay CAN bus data.

Let’s start by setting up the virtual CAN (vcan) interface. Open a new terminal window, navigate to the ICSim directory, and run the setup script:

cd Documents/Car_Hacking/ICSim && ./setup_vcan.sh

Now, in the same terminal, start the ICSim simulator, specifying the vcan0 interface:

./icsim vcan0

Open a second terminal window, navigate back to the ICSim directory, and launch the controls interface, also specifying vcan0:

cd Documents/Car_Hacking/ICSim && ./controls vcan0

You should now see the ICSim application window open, displaying the virtual instrument cluster.

The ICSim application window showing the virtual instrument cluster with all doors initially locked.

You can interact with the virtual vehicle using keyboard controls. For example, the LEFT arrow key activates the left turn signal, and the UP arrow key increases the speedometer, simulating acceleration. To unlock doors, use Right SHIFT + A|B|X|Y (for individual doors) or Left SHIFT then Right SHIFT (for all doors). Left SHIFT + door keys will lock the doors.

Experiment with these controls to familiarize yourself with the simulator and observe how it responds to different inputs. For our replay attack, we’ll focus on locking and unlocking all doors. Start with all doors locked, then unlock all doors (Left SHIFT then Right SHIFT) and then lock them again (Right SHIFT then Left SHIFT).

Now, open a third terminal window and create a “Demo” directory within “Car_Hacking” to keep our captured data organized:

cd Documents/Car_Hacking && mkdir Demo && cd Demo

In this “Demo” directory, we’ll use the candump utility to capture CAN bus traffic on the vcan0 interface. We’ll use the -l option to log the captured data to a file.

First, let’s demonstrate the volume of CAN bus traffic. Start candump with logging, let it run for about 5 seconds without performing any actions in the simulator, and then stop it with CTRL+C:

candump vcan0 -l

ls

wc -l candump-YYYY-MM-DD_HHMMSS.log # Replace YYYY-MM-DD_HHMMSS with the actual log file name

You’ll notice a surprisingly large number of packets captured even in just a few seconds of passive listening, highlighting the constant communication on the CAN bus.

Now, let’s capture the specific CAN bus traffic associated with locking and unlocking the doors. We’ll perform the following steps quickly to minimize extraneous data in our log file:

Start candump with logging in the “Demo” terminal.
Activate the “CANbus Control Panel” window.
Unlock all doors (Left SHIFT then Right SHIFT).
Lock all doors (Right SHIFT then Left SHIFT).
Click back into the candump terminal.
Press CTRL+C to stop the capture.

Before starting, delete any previous log files in the “Demo” directory to avoid confusion. Then, execute the capture process:

rm candump-*.log # Remove any old candump log files
candump vcan0 -l

Perform the unlock and lock actions in the simulator as described above, then stop candump with CTRL+C.

Use wc -l again to check the number of lines in your new log file. It should be significantly smaller than the initial passive capture, but still contain the CAN packets related to door locking and unlocking.

Now, we’ll use the canplayer utility to replay this captured log file back onto the vcan0 interface and observe the ICSim window. If successful, replaying the log should cause the virtual car doors to unlock and then lock again. Use the -I option with canplayer to specify the input log file:

canplayer -I candump-YYYY-MM-DD_HHMMSS.log # Replace YYYY-MM-DD_HHMMSS with your actual log file name

If you observe the doors unlocking and locking in the ICSim simulator when you run canplayer, you’ve successfully executed a replay attack!

Isolating the Door Control Packets with Kayak

While canplayer replays the entire log, we want to pinpoint the specific CAN packets responsible for door control. We can use a binary search-like approach, repeatedly halving the log file and replaying it until we isolate the relevant packets.

Using Kayak will significantly streamline this analysis process. Kayak is a powerful GUI tool designed for analyzing CAN bus traffic.

First, start Kayak. From the “Kayak” directory, run:

./run.sh

In Kayak, you’ll need to configure the CAN interface. Go to File -> Open Interface. Select CAN Interface and in the configuration, choose Mode: SocketCAN, Bitrate: 500000, and Interface: vcan0. Click Ok.

Now, in Kayak, click the Record button to start capturing CAN traffic. Similar to our candump process, quickly unlock and lock the doors in the ICSim simulator. Then, click the Stop button in Kayak to halt the capture.

Kayak will now display the captured CAN frames in a table. You can filter and analyze these frames to identify the door control packets. Look for patterns or changes in the CAN IDs and data fields when you performed the unlock/lock actions.

To further refine the search, you can use Kayak’s filtering capabilities. Experiment with filtering by CAN ID, data field values, or timestamps to isolate potential door control packets.

Once you suspect a specific CAN frame or a small set of frames are responsible for door control, you can use Kayak’s Transmit function to replay these individual frames. Select the frame(s) in Kayak, right-click, and choose Transmit selected frames. Observe if replaying these frames triggers the door lock/unlock action in the ICSim simulator.

Through iterative capture, filtering, and replay within Kayak, you can efficiently isolate the exact CAN packets that control the door locks.

Analyzing Door Control Data with Kayak

Once you’ve identified the CAN packets controlling the door locks using Kayak, you can delve deeper into analyzing the data field to understand how different bits and bytes affect door behavior.

Let’s assume, through the isolation process, you’ve identified a CAN ID (e.g., 19B in hexadecimal) that seems to control the doors. By observing the data field of packets with this ID during lock and unlock actions, you might notice specific bytes or bits changing.

Kayak’s interface allows you to examine the data field in hexadecimal and binary formats. By comparing CAN packets captured during different door actions (e.g., unlock all, lock all, unlock individual doors), you can deduce which bits within the data field correspond to specific doors or actions.

For example, you might find that the third byte of the data field is crucial for door control. By analyzing variations in this byte across different actions, you might discover a bitmask where each bit represents a specific door and its lock/unlock state.

As demonstrated in the original article, by systematically testing different data values (e.g., 0x00, 0x0F, 0x08, 0x04, 0x02, 0x01 in the third byte), you can map each bit to a specific door and action (lock/unlock). Kayak’s transmit functionality is invaluable for quickly testing these hypotheses by sending modified CAN packets and observing the results in the ICSim simulator.

Expanding Your Car Hacking Knowledge

This tutorial has provided a hands-on introduction to car hacking using Kayak and focusing on a CAN bus replay attack to control door locks. However, this is just the tip of the iceberg.

To deepen your understanding and skills in car hacking, consider exploring these resources:

“The Car Hacker’s Handbook” by Craig Smith: A comprehensive guide to automotive cybersecurity, covering a wide range of topics from CAN bus analysis to ECU reverse engineering.
Car Hacking Village: A community and platform dedicated to car hacking education, workshops, and events.
CSS Electronics and Illmatics Car Hacking Resources: Online resources offering tutorials, articles, and tools related to CAN bus and car hacking.

Conclusion: Ethical Exploration and Responsible Innovation

In this guide, we’ve explored the practical steps of using the Kayak car hacking tool to perform a replay attack on a virtual vehicle, specifically targeting door lock control. We’ve covered setting up the necessary tools, capturing and replaying CAN bus data, isolating relevant packets, and analyzing the data field to understand door control mechanisms.

Remember, the knowledge and techniques presented here should be used ethically and responsibly. Car hacking, while fascinating and valuable for research and security improvement, carries potential risks if misused. Always prioritize ethical considerations, respect legal boundaries, and practice in safe, controlled environments like virtual simulators before experimenting on physical vehicles.

By responsibly exploring car hacking, you can contribute to a deeper understanding of automotive cybersecurity, potentially leading to safer and more secure vehicles in the future. Tools like Kayak empower researchers and enthusiasts to delve into the complexities of vehicle networks, fostering innovation and responsible advancements in the automotive industry.