Primer paso de la investigacion. Se aportan el .apk, las carpetas con el apk extraido y el apk descompilado. El archivo API_DOCUMENTATION.md es un archivo donde se anotaran los descubrimientos del funcionamiento de la API, y los .py son scripts para probar la funcionalidad de la API con los métodos que vayamos encontrando. Finalmente, los archivos .js son scripts de Frida para extraer informacion de la APP durante la ejecucion.

apk_decompiled/sources/com/google/firebase/messaging/FcmExecutors.java

@@ -0,0 +1,73 @@
+package com.google.firebase.messaging;
+
+import android.annotation.SuppressLint;
+import com.google.android.gms.common.util.concurrent.NamedThreadFactory;
+import com.google.firebase.messaging.threads.PoolableExecutors;
+import com.google.firebase.messaging.threads.ThreadPriority;
+import java.util.concurrent.Executor;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledThreadPoolExecutor;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+
+/* JADX INFO: Access modifiers changed from: package-private */
+/* loaded from: classes3.dex */
+public class FcmExecutors {
+    private static final String THREAD_FILE = "Firebase-Messaging-File";
+    static final String THREAD_FILE_IO = "Firebase-Messaging-File-Io";
+    private static final String THREAD_INIT = "Firebase-Messaging-Init";
+    private static final String THREAD_INTENT_HANDLE = "Firebase-Messaging-Intent-Handle";
+    private static final String THREAD_NETWORK_IO = "Firebase-Messaging-Network-Io";
+    static final String THREAD_RPC_TASK = "Firebase-Messaging-Rpc-Task";
+    private static final String THREAD_TASK = "Firebase-Messaging-Task";
+    private static final String THREAD_TOPICS_IO = "Firebase-Messaging-Topics-Io";
+
+    private FcmExecutors() {
+    }
+
+    @SuppressLint({"ThreadPoolCreation"})
+    private static Executor newCachedSingleThreadExecutor(String str) {
+        return new ThreadPoolExecutor(0, 1, 30L, TimeUnit.SECONDS, new LinkedBlockingQueue(), new NamedThreadFactory(str));
+    }
+
+    @SuppressLint({"ThreadPoolCreation"})
+    public static ExecutorService newFileExecutor() {
+        return Executors.newSingleThreadExecutor(new NamedThreadFactory(THREAD_FILE));
+    }
+
+    public static Executor newFileIOExecutor() {
+        return newCachedSingleThreadExecutor(THREAD_FILE_IO);
+    }
+
+    @SuppressLint({"ThreadPoolCreation"})
+    public static ScheduledExecutorService newInitExecutor() {
+        return new ScheduledThreadPoolExecutor(1, new NamedThreadFactory(THREAD_INIT));
+    }
+
+    @SuppressLint({"ThreadPoolCreation"})
+    public static ExecutorService newIntentHandleExecutor() {
+        return PoolableExecutors.factory().newSingleThreadExecutor(new NamedThreadFactory(THREAD_INTENT_HANDLE), ThreadPriority.HIGH_SPEED);
+    }
+
+    @SuppressLint({"ThreadPoolCreation"})
+    public static ExecutorService newNetworkIOExecutor() {
+        return Executors.newSingleThreadExecutor(new NamedThreadFactory(THREAD_NETWORK_IO));
+    }
+
+    public static Executor newRpcTasksExecutor() {
+        return newCachedSingleThreadExecutor(THREAD_RPC_TASK);
+    }
+
+    @SuppressLint({"ThreadPoolCreation"})
+    public static ExecutorService newTaskExecutor() {
+        return Executors.newSingleThreadExecutor(new NamedThreadFactory(THREAD_TASK));
+    }
+
+    @SuppressLint({"ThreadPoolCreation"})
+    public static ScheduledExecutorService newTopicsSyncExecutor() {
+        return new ScheduledThreadPoolExecutor(1, new NamedThreadFactory(THREAD_TOPICS_IO));
+    }
+}