Wireless devices are typically very personal items to their holders, such as cell phones and handheld computers. As such, these devices are a treasure trove of personal information that could be of great use to an attacker including contact lists and text messages. Bluetooth can also be a vehicle for spreading viruses across mobile devices
Bluetooth is an open wireless technology standard for transmitting fixed and mobile electronic device data over short distances. Bluetooth was introduced in 1994 as a wireless substitute for RS-232 cables.
Bluejacking refers to the act of sending anonymous Bluetooth text messages and images from your device to surrounding cell phones by creating a new contact and typing in a personal message in the Name field on the contact. Once created, the message is then sent to any Bluetooth device that you’ve discovered in the area and is immediately displayed on its screen. There is really no special software required for this action, and the legalities of it remain unclear. It has definitely become a vehicle for practical jokes by many in urban areas but can be used as part of a larger social engineering attack.
With Wireless devices, the user may not initially know that there are other Wireless devices nearby, so a method is required to find them. The Bluetooth equivalent of plugging in a cable is the forming of a connection. The checks on communications protocols and application compatibility are actually done once a basic Bluetooth link is established, and are called service discovery.