Welcome to Cybersecurity in 31 Days. I’m Malan Faya, your host. Today is Day 4. To view previous posts, click here.

Remember the days of Infrared? Though old school now, a hacker would at least need to connect with your mobile device through his or her own Infrared as well. This way, it’s easy to know who compromised your mobile device. But with Bluetooth? Not likely.

Bluetooth is a smart technology. You get to easily connect and sync without physical contact between devices. But Bluetooth can also be a serious danger to your security. Through Bluetooth, hackers use various methods, such as bluejacking,  bluesnarfing, and bluebugging, to get at your mobile device. Beware.

Hackers can steal your personal information by using an open Bluetooth connection to compromise your electronic devices. When your Bluetooth is on, it is constantly open to—and waiting for—potential connections. A hacker will start scanning for devices that have their Bluetooth on. Once the hacker is able to identify an electronic device that is vulnerable, the hacker can then carry out the attack. For this attack, the vulnerable device doesn’t need to be connected with anything. And the attack can even work when the Bluetooth on the victim’s device is already paired to something else. The hacker will be able to take control and have access of the victim devices. Always turn off Bluetooth if you aren’t using it or if you’re near anyone you don’t trust.

It is not an all-night party for Bluetooth-enabled hackers though. Bluetooth technology keeps improving and updates to mobile-device firmware and new security measures are minimizing risks. Hackers may find it too expensive to hack acquire the software and hardware they need to hack you through Bluetooth (except you are Donald Trump). But you never know.

So always ensure that you turn off your Bluetooth only when it is not needed.