Be Cautious! Devices with BlueTooth can be Hacked without interaction, including mobile phones.

Armis Labs has found out a major vulnerability in mobile, desktop, and IoT operating systems that has bluetooth connections enabled. It includes OS'es liek Android, iOS, Windows, and Linux.
It can spread and exploited through air, i.e. via Bluetooth. This can be done without even touching the devices or getting physical access to them. Hence it is more dangerous as it does not require human interaction with the device under consideration.

The scary part is that the bluetooth device does not require pairing and even does not require the device in question to be in discoverable mode.
The vulnerability can lead to taking complete control of the device, access data and can disseminate malware that includes ransomware to the nearby devices.
In fact there are multiple vulnerabilities that has been found and large portion of mobile phones are vulnerable to it that includes some big names.
One can check if their device is infected or not by using an app available in google play by the name "BlueBorne Vulnerability Scanner".

Many vendors have provided patch for the same.
Make sure that you update your devices.