Consumer watchdog Which? found 40 per cent of Android users have been using old versions of the Google-made OS that no longer receive vital updates.
The most at-risk phones are any that run Android 4 or older – however, those using devices on Android 7.0 that can’t update to a newer version should also be concerned.
The study, based on Google data, highlights the importance of using up-to-date software to avoid being at risk of data theft, ransom demands and other malware attacks.
The current software version is Android 10 while Android 9 and 8 are still ‘in theory’ getting security updates too and are safe to use.