Barcode Scanner app developed by LAVABIRD LTD self-updated and took over the users’ devices using malicious code now tagged by security vendors as trojan malware. Malwarebytes malware researcher Nathan Collier said many users had the app installed on their mobile devices for long periods of time (one user had it installed for several years) Google has removed the popular app from the Play Store after receiving the disclosure in December. Despite this, there might still be millions of other devices still affected and displaying unwanted ads to its unwitting userbase.
Source: https://www.bleepingcomputer.com/news/security/android-app-joins-the-dark-side-sends-malware-update-to-millions/