The American fugitive whistleblower Edward Snowden has claimed that the US National Security Agency (NSA), which works with the UK’s Government Communications Headquarters (GCHQ), can eavesdrop through the mic inside an iPhone even when the device is switched off. The claim has been confirmed by several experts, reports Sina’s tech news web portal.
Snowden said the NSA and GCDQ have worked together on the technique enabling their agents to secretly eavesdrop on iPhone users. “They can absolutely turn them on with the power turned off to the device,” Snowden said.
Eric McDonald, a hardware engineer in Los Angeles, backed up Snowden’s claim, saying that when the mobile phone is switched off it actually enters a low-power mode that leaves key communication chips active, including the option of remotely activating the mic. The phone is not off; it is “playing dead.”
“The screen would look black and nothing would happen if you pressed buttons but it’s conceivable that the baseband (the cellular function) is still on, or turns on periodically,” he said. It would be very difficult to discover if one’s mobile phone had been tapped.
Security consultant Robert David Graham said the technique Snowden referred to is probably an implant. An implant means that the NSA listens to one’s mobile phone and installs hardware or software on it. “Yes, an implant gives the NSA full control over your phone but it’s difficult getting the implant on your phone in the first place,” he said.
Once NSA installs an implant in the mobile phone, they can activate it remotely. It is because the mobile phone is not actually switched off when it appears to be. Graham said that the technique can be used through the internet or the phone’s cellular functions. It can also be installed if someone has access to the user’s mobile phone.
To ensure that your mobile phone is not being tapped, you must make it enter the so-called device firmware update mode (DFU mode). First plug the iPhone into any power outlet or USB port. Press the on/off button, and after three seconds press the home button. Keep both buttons pressed for ten seconds. Release the power button but continue pressing the home button for another ten to fifteen seconds. The mobile phone will then enter DFU mode.