Watch out for Wifi networks when using Android devices

If you are using an Android phone that has been released within the last three years, it may reveal the names of all the Wi-Fi networks you've ever connected to.

A new investigation from the Electronic Frontier Foundation (EFF) on a feature called the Preferred Network Offload (PNO) was first introduced at Honeycomb OS, showing that Android smartphones can reveal a list of Wi-Fi networks. each connection when searching for suitable network even when the phone is still in sleep mode.

Android features revealing the list of Wifi networks

This leads to the risk that users can be monitored and recorded the places that have been and Wifi connection on the phone such as " Ms. X ", " Mr. Y's apartment " . etc.

However, it is not difficult to prevent this feature from working, just go to the " Advanced Wi-Fi " settings and disable the " Keep Wi-Fi on during sleep " feature to prevent the device from checking. Wifi network list even in sleep mode. In return, you will see a slight increase in battery life.

Turn off Keep Wi-Fi on during sleep mode

Devices running iOS 6, 7, 8 of Apple are not affected by this error, although EFF has reported a number of data leaks in devices running iOS 5. Laptops run the system. OS X or Windows 7 are also likely to be affected, but they do not have a Sleep Mode protocol similar to Android so the possibility of data leakage is much more limited.