Watchdog Which? has suggested that more than a billion Android devices are vulnerable to hacking because they are not being protected by security updates any more.
As a result of this vulnerability, users worldwide are exposed to the danger of data theft, ransom demands, and other malware attacks.
Devices released in 2012 or earlier are particularly at risk.
Data from Google itself suggests that 42.1% of Android users are on version 6.0 of its operating system or below.
No security patches had been issued for the Android system in 2019 for versions below 7.0, according to the Android security bulletin.
From this data Which? deduced that every two out of five Android users worldwide were no longer receiving security updates.
The watchdog then tested five phones, a Motorola X, a Samsung Galaxy A5, a Sony Xperia Z2, an LG/Google Nexus 5, and a Samsung Galaxy S6, by asking anti-virus lab AV Comparatives to infect them with malware.
The malware succeeded in penetrating security on every phone, creating multiple infections on some.
Which? has said that it shared its findings with Google, but the tech giant "failed to provide reassurance that it has plans in place to help users whose devices were no longer supported".
