The FBI and U.S. National Highway Traffic Safety Administration Thursday warned vehicle owners and automakers of possible hacking. A joint statement by the two agencies said that motor vehicles are “increasingly vulnerable” to hacking.

The bulletin said criminals are likely to make use of online vehicle software updates by sending fake “email messages to vehicle owners who are looking to obtain legitimate software updates. Instead, the recipients could be tricked into clicking links to malicious websites or opening attachments containing malicious software.”

“Modern motor vehicles often include new connected vehicle technologies that aim to provide benefits such as added safety features, improved fuel economy, and greater overall convenience,” the FBI and NHTSA said in the statement. “Aftermarket devices are also providing consumers with new features to monitor the status of their vehicles. However, with this increased connectivity, it is important that consumers and manufacturers maintain awareness of potential cyber security threats.”

Last July, Fiat Chrysler Automobiles recalled 1.4 million Dodges, Jeeps, Rams and Chryslers after discovering a software flaw in the cars’ radios which made them vulnerable to hackers. The move was triggered after Wired magazine published a video of one of their journalists driving a Jeep as it was hacked on the highway. The security researchers who hacked the vehicle were able to turn on the moving vehicle’s windshield wipers, take control of the volume settings and ultimately steer it into a ditch.

The FBI and NHTSA also advised people to keep their vehicle’s software up to date and keep an eye out for possible recalls. The agencies also cautioned drivers against giving physical access of their vehicles to strangers. “In much the same way as you would not leave your personal computer or smartphone unlocked, in an unsecure location, or with someone you don’t trust, it is important that you maintain awareness of those who may have access to your vehicle,” the bulletin stated.