Snowden told the BBC's Panorama that the GCHQ has developed a hacking suite dubbed Smurf Suite, it can hack any mobile by sending an encrypted text message.
There is no way to stop secret services spying on users' Smartphones, this is the last revelation of the US whistleblower Edward Snowden.
Snowden told the BBC's Panorama that the British intelligence agency, the GCHQ, is able to hack any mobile device, just by sending it an encrypted text message that would pass unnoticed by the handset's owner.
"It's called an 'exploit'," he said. "That's a specially crafted message that's texted to your number like any other text message but when it arrives at your phone it's hidden from you. It doesn't display. You paid for it [the phone] but whoever controls the software owns the phone."
Snowden doesn't refer mass-monitoring activities conducted by the GCHQ, but confirmed the abilities of the UK and US intelligence agencies to hack smartphones.
"They want to own your phone instead of you," he said.
Edward Snowden has spoken about a collection of secret intercept capabilities dubbed the "Smurf Suite" developed by the GCHQ.
"Dreamy Smurf is the power management tool which means turning your phone on and off with you knowing," he said.
"Nosey Smurf is the 'hot mic' tool. For example if it's in your pocket, [GCHQ] can turn the microphone on and listen to everything that's going on around you – even if your phone is switched off because they've got the other tools for turning it on." reported the BBC. "Tracker Smurf is a geo-location tool which allows [GCHQ] to follow you with a greater precision than you would get from the typical triangulation of cellphone towers."
The Smurf Suite also includes a tool dubbed Paranoid Smurf, which is used by GCHQ agents to armor manipulation of the phone, making impossible more difficult for any technician to realize
"It's a self-protection tool that's used to armour [GCHQ's] manipulation of your phone. For example, if you wanted to take the phone in to get it serviced because you saw something strange going on or you suspected something was wrong, it makes it much more difficult for any technician to realise that anything's gone amiss."
Once the UK intelligence has compromised a mobile device, it is able to spy on the target and the surrounding environment [The GCHQ agents know] "who you call, what you've texted, the things you've browsed, the list of your contacts, the places you've been, the wireless networks that your phone is associated with."
"And they can do much more. They can photograph you".
Snowden also mentioned the collaboration between GCHQ and the NSA, he defined the British Agency a subsidiary of the US one.
"GCHQ is to all intents and purposes a subsidiary of the NSA." "They [the NSA] provide technology, they provide tasking and direction as to what they [GCHQ] should go after."
This means that also the NSA has the same spying capabilities implemented in the Smurf Suite. The Intelligence agency has invested $1bn in an effort to track suspects of terrorist activities and pedophilia.
Mr Snowden anyway remarked that investigations conducted by the Intelligence Agencies requested the collection of huge quantity of data.
"They say, and in many cases this is true, that they're not going to read your email, for example, but they can and if they did you would never know," he said.
On the other end, a spokesman of the British intelligence explained that the GCHQ operates respecting the law and policy framework.
"All of GCHQ's work is carried out in accordance with a strict legal and policy framework, which ensures that our activities are authorised, necessary and proportionate, and that there is rigorous oversight, including from the secretary of state, the interception and intelligence services commissioners and the Parliamentary Intelligence and Security Committee. All our operational processes rigorously support this position."