published April 25, 2019
The Vivo V7 Android device with a build fingerprint of vivo/1718/1718:7.1.2/N2G47H/compil11021857:user/release-keys contains a platform app with a package name of com.vivo.smartshot (versionCode=1, versionName=3.0.0). This app contains an exported service named com.vivo.smartshot.ui.service.ScreenRecordService that will record the screen for 60 minutes and write the mp4 file to a location of the user's choosing. Normally, a recording notification will be visible to the user, but we discovered an approach to make it mostly transparent to the user by quickly removing a notification and floating icon. The user can see a floating icon and notification appear and disappear quickly due to quickly stopping and restarting the service with different parameters that do not interfere with the ongoing screen recording. The screen recording lasts for 60 minutes and can be written directly to the attacking app's private directory.