Mobile devices typically support cellular networks as well as local wireless networks (WiFi, Bluetooth). Both of these types of networks can host different classes of threats:

• Network exploitstake advantage of flaws in the mobile operating system or other software that operates on local or cellular networks. Once connected, they can install malware on your phone without your knowledge.
• Wi-Fi Sniffingintercepts data as it is traveling through the air between the device and the Wi-Fi access point. Many applications and web pages do not use proper security measures, sending unencrypted data across the network that can be easily read by someone who is grabbing data as it travels.
• Bluejackingis sending nameless, unwanted messages to other users with Bluetooth-enabled mobile phones or laptops. Bluejacking depends on the capability of Bluetooth phones to detect and contact another Bluetooth enabled devices. The Bluejacker uses a feature originally proposed for exchanging contact details or electronic business cards. He or she adds a new entry in the phone’s address book, types in a message, and chooses to send it via Bluetooth.The phone searches for other Bluetooth phones and, if it finds one, sends the message.
• Bluesnarfingis the theft of data from a Bluetooth phone. Like Bluejacking, Bluesnarfing depends on the ability of Bluetooth-enabled devices to detect and contact others nearby. In theory, a Bluetooth user running the right software on their laptop can discover a near by phone, connect to it without your confirmation, and download your phonebook, pictures of contacts and calendar.

Your mobile phone’s serial number can also be downloaded and used to clone the phone. You should turn off Bluetooth or set it to “undiscoverable”. The undiscoverable setting allows you to continue using Bluetooth products like headsets, but means that your phone is not visible to others.