The Symphony G100 Android device with a build fingerprint of Symphony/G100/G100:8.1.0/O11019/1530618779:user/release-keys contains a pre-installed app with a package name of com.mediatek.wfo.impl app (versionCode=27, versionName=8.1.0) that allows any app co-located on the device to modify a system property through an exported interface without proper authorization.