Scientists have claimed that millions of people using Android apps are seeing their personal data leaked as a result.
Reports have claimed research by University of Leibniz and the computer science department at the Philipps University of Marburg found many apps that failed to safely implement a scrambling system to protect data.
13,500 Android apps were tested, and just under eight per cent failing to protect account login details.
Failures included attackers being able to reroute transfers of funds and disable security systems.
Some of the apps included in the tests had been downloaded millions of times, said those carrying out the research.
Google has yet to comment.