Introduction

I suspected that additional information might be included in the intent used to launch the app. Through debugging, I discovered that a bundle named activity_options is passed as this additional information.

While investigating the values in this bundle, I found that the key android:activity.packageName contains the value com.samsung.knox.securefolder.

// Activity
val packageName = intent.getBundleExtra("activity_options")
  ?.getString("android:activity.packageName", "empty")
  ?: "empty"

android:activity.packageName is defined in the ActivityOptions.java file under the name KEY_PACKAGE_NAME. As indicated in the description, the value for this key represents the package that created these options, which allows us to understand that the app was launched from Secure Folder.

Screenshots 📱

Default	Secure Folder

Warning ⚠️

This is a fact discovered through reverse engineering, and it may not function correctly following future updates to `Secure Folder.