Bluetooth technology offers convenience - from hands-free phone calls to wireless file-sharing to playing music on a vehicle's speakers. But leaving your Bluetooth on all the time can be dangerous, and hackers are exploiting the technology to access private information, spread malicious software and more.BlueBorne, an "attack vector" that can infect iOS, Android, Windows and Linux devices, is spread through the air, according to Palo Alto-based cybersecurity firm Armis.The virus allows hackers to "take control of devices, access corporate data and networks, penetrate secure 'air-gapped' networks and spread malware." BlueBorne can penetrate anything - computers, smartphones, tablets and the ever-growing world of continuously-connected gadgets like televisions, light bulbs and refrigerators. Even more alarming - the attacker's device doesn't have to be paired to the victim's to launch an assault. The campaign works in stages - once a hacker finds an active Bluetooth device nearby, he identifies its unique MAC address. He then determines its operating system and adjusts the attack, exploiting any weaknesses. From there, he gains control of the device and can use it for a multitude of purposes. "The BlueBorne attack vector has several qualities which can have a devastating effect when combined," Armis explains. "By spreading through the air, BlueBorne targets the weakest spot in the networks’ defense – and the only one that no security measure protects. Spreading from device to device through the air also makes BlueBorne highly infectious. Since the Bluetooth process has high privileges on all operating systems, exploiting it provides virtually full control over the device."Here's how to protect yourself from BlueBorne:AndroidAll Android phones and tablets are vulnerable, with the exception of devices using Bluetooth Low Energy.How to fix: Update your Android with Google's latest security patch, which was open to Android partners last month and is part of September's Security Update and Bulletin. Ensure that you have the most recent Security Patch Level, which was released earlier this month. WindowsAll Windows computers since Windows Vista could be affected.How to fix: Update Windows devices with Microsoft's latest security patches, which were issued in July.LinuxAll Linux devices using BlueZ could be impacted, including Samsung's Gear S3 smartwatch, its Family Hub refrigerator, and its line of smart televisions. How to fix: The latest Linux patches can be found here.iOSBlueBorne can affect all iPhones, iPads and iPods running iOS 9.3.5 or lower, and all Apple TVs running iOS 7.2.2 or lower. How to fix: Make sure your device is running iOS 10, which was released in July. If your device hasn't been updated, the easiest way to avoid BlueBorne is to disable its Bluetooth and use it as little as possible.