Except one. An app called SysAdminTrack. That was a bit weird: it sounded like some bit of essential code to keep the phone running. And yet it was the only app that had been downloaded. Its icon was a pair of crossed spanners encircled by an old-fashioned cog. I opened the app and the icon enlarged to fill the mobile’s small screen, a short menu appearing on the left-hand side. Just four items in the menu: ‘About’, ‘Version’, ‘Upgrade’ and ‘Permissions’. The first three yielded almost nothing, the briefest of text saying where it had been written, what year, some code writer’s pseudonym and associated gobbledygook. It didn’t actually seem to do anything. It wasn’t a game, productivity app, social media app – none of those things.

The ‘Permissions’ tab was more revealing. When I tapped it, a drop-down list appeared, detailing what the app could use on the phone. It had permission to access and use both front and rear cameras for stills and video, plus the microphone for audio, GPS location, internet browser, text messages, emails, apps and internal storage. In other words, permission to access pretty much everything on my phone – for no obvious reason.

I went back to the main menu, scoured the other options for more information, and finally gave up. SysAdminTrack had been created in 2014, somewhere in the USA – that was all the information it yielded.

A string of results came up for it on Google, a Wikipedia entry at the top:

‘SysAdminTrack is one of the names given to a piece of software originally developed by a white hat hacking group referred to as the Electronic Orchard Collective. They developed SysAdminTrack to demonstrate the weaknesses of cellphone operating systems, and their vulnerabilities to potential intrusion by government agencies. The app exploits various vulnerabilities to allow access to the phone’s functions from a third party cellphone user. That user can then operate the phone’s functionality from a remote location, including access to the cameras and microphone, which can be activated without any of the standard visual cues. It keeps running even when the app is closed.

‘The app has been banned in the USA because of fears over privacy and the potential for users to unwittingly reveal personal information, pictures and video to third parties.’

I felt a shock of realisation, as if I had grabbed hold of an electrified fence. If it could record audio, and if this app was installed on my previous phones as well, it could have recorded every conversation I’d had – with my solicitor, with the police, everyone I’d come into contact with. My mobile was always there. And if it could access texts and emails remotely as well, it could have sent that audio to a third party.

A lot of ifs. But who could have done it?