Google led a takedown disrupting a 1.3M Android device botnet centered on TV set-top boxes.

Google concluded with high confidence that hardware maker Videostrong intentionally embedded an x.cpe system-level backdoor into firmware over several years to sell criminal access.

The problem mainly affects internet-connected television sets, known as set-top boxes, but also other devices such as karaoke machines, telemedicine equipment and digital display screens. Videostrong, based in Shenzhen, China, has been embedding the hidden program in many models and brands of devices for several years.

How the secret program worked

The program, known as x.cpe, operated in secret with full system access to devices and disabled security checks in Google's app store.…