Android based smartphones from vendors such as Ulefone and Krüger&Matz contain "com.pri.factorytest" application preloaded onto devices during manufacturing process. The application "com.pri.factorytest" (version name: 1.0, version code: 1) exposes a ”com.pri.factorytest.emmc.FactoryResetService“ service allowing any application to perform a factory reset of the device.  Application update did not increment the APK version. Instead, it was bundled in OS builds released later than December 2024 (Ulefone) and April 2025 (Krüger&Matz).

The Ulefone Armor 5 Android device with a build fingerprint of Ulefone/Ulefone_Armor_5/Ulefone_Armor_5:8.1.0/O11019/1528806701: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.

ulefone