Modern cars contain tens of specialized computers that control everything from infotainment functions to steering and brakes. The pressing need to protect these computers from hackers will likely open up a new market for car-related software security products.
Karamba Security, a start-up based in Ann Arbor, Michigan, is one of the companies that has stepped up to answer this demand. The company’s anti-malware technology, unveiled Thursday, is designed to protect externally accessible electronic control units (ECUs) found in connected cars.
These controllers, like those that handle handle telematics, infotainment and on-board diagnostics, can be accessed via Wi-Fi, Bluetooth or even the Internet, so they can serve as entry points for hackers into a car’s network.
A modern car can have over 100 ECUs talking to each other over a local network called the CAN (Controller Area Network) Bus. The communication protocol used on this network does not have security features like authentication or encryption built in because it is designed for speed.
Unfortunately this means that attackers who gain access to the CAN Bus through a vulnerability in an ECU can send valid commands to other ECUs that will be accepted and executed.
This is what security researchers Charlie Miller and Chris Valasek did last year when they demonstrated an attack against the infotainment system found inside the Jeep Cherokee and other Fiat Chrysler vehicles.
Their exploit, which was executed over the Internet using the mobile data connection installed in a car, gained access to the CAN Bus and sent commands to the car’s ECUs in order to remotely disable its brakes or control its steering. The attack forced Chrysler to recall 1.4 million automobiles so they could be patched.
Filtering the CAN Bus traffic by adding a firewall to detect rogue instructions is not practical, because it would introduce unacceptable delays. When a sensor sends a command to an ECU that controls a critical safety function, every millisecond counts.
Karamba’s approach is to instead focus on protecting the “gates”—the externally connected controllers. Its anti-malware technology runs on these ECUs, which are not usually critical, and prevents any code that’s not part of the factory settings from running.
To achieve this, the technology builds a whitelist of all the binaries, processes, scripts and network behavior that the ECU manufacturer intended the controller to have. Anything that’s not on that whitelist is then blocked.
The system can also detect “droppers,” the small bits of code or instructions that get executed after a vulnerability is exploited. Their purpose is to install the malware program that can then be used by the hacker to tamper with the car’s functions.
When droppers are detected, Karamba’s technology alerts the OEM or system supplier, providing a complete audit trail of the source and path of the code so that vulnerabilities can be identified and patched.
Since Karamba’s system only allows code that’s part of the defined factory settings to run, there’s no risk of false positives, and the system doesn’t require any updates unless the ECU firmware changes.
Karamba’s technology can be integrated into ECUs during their development phase, but can also be retrofitted to existing controllers during a car maintenance or servicing operation. The installation process includes a quality check of the ECU to ensure that it’s performing according to specifications.
Last month, the FBI and the National Highway Traffic Safety Administration put out a public service announcement warning about the risk of car hacking. The organizations advised car owners to be careful of what aftermarket devices they connect to their cars, to be aware of who has physical access to their vehicles and especially their diagnostics ports and to keep informed about any software updates or recalls for their car models.