Objection Tutorial - HackTricks

# Objection Tutorial

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## Introduction

objection - Runtime Mobile Exploration

Objection is a runtime mobile exploration toolkit, powered by Frida. It was built with the aim of helping assess mobile applications and their security posture without the need for a jailbroken or rooted mobile device.

Note: This is not some form of jailbreak / root bypass. By using `objection`, you are still limited by all of the restrictions imposed by the applicable sandbox you are facing.

### Resume

The goal of objection is let the user call the main actions that offers Frida. Otherwise, the user will need to create a single script for every application that he wants to test.

## Tutorial

For this tutorial I am going to use the APK that you can download here:

app-release.zip

Or from its original repository (download app-release.apk)

### Installation

    pip3 install objection

### Connection

Make a regular ADB conection and start the frida server in the device (and check that frida is working in both the client and the server).

If you are using a rooted device it is needed to select the application that you want to test inside the --gadget option. in this case:

    frida-ps -Uai
    objection --gadget asvid.github.io.fridaapp explore

### Basic Actions

Not all possible commands of objections are going to be listed in this tutorial, only the ones that I have found more useful.

#### Environment

Some interesting information (like passwords or paths) could be find inside the environment.

    env

#### Frida Information

    frida

#### Upload/Download

    file download <remote path> [<local path>]
    file upload <local path> [<remote path>]

#### Import frida script

    import <local path frida-script>

#### SSLPinning

    android sslpinning disable #Attempts to disable SSL Pinning on Android devices.

#### Root detection

    android root disable  #Attempts to disable root detection on Android devices.
    android root simulate #Attempts to simulate a rooted Android environment.

#### Exec Command

    android shell_exec whoami

#### Screenshots

    android ui screenshot /tmp/screenshot
    android ui FLAG_SECURE false  #This may enable you to take screenshots using the hardware keys

### Static analysis made Dynamic

In a real application we should know all of the information discovered in this part before using objection thanks to static analysis. Anyway, this way maybe you can see something new as here you will only have a complete list of classes, methods and exported objects.

This is also usefull if somehow you are unable to get some readable source code of the app.

#### List activities, receivers and services

    android hooking list activities

    android hooking list services
    android hooking list receivers

Frida will launch an error if none is found

#### Getting current activity

    android hooking get current_activity

#### Search Classes

Lets start looking for classes inside our application

    android hooking search classes asvid.github.io.fridaapp

#### Search Methods of a class

Now lets extract the methods inside the class MainActivity:

    android hooking search methods asvid.github.io.fridaapp MainActivity

#### List declared Methods of a class with their parameters

Lets figure out wich parameters does the methods of the class need:

    android hooking list class_methods asvid.github.io.fridaapp.MainActivity

#### List classes

You could also list all the classes that were loaded inside the current applicatoin:

    android hooking list classes #List all loaded classes, As the target application gets usedmore, this command will return more classes.

This is very useful if you want to hook the method of a class and you only know the name of the class. You coul use this function to search which module owns the class and then hook its method.

### Hooking being easy

#### Hooking (watching) a method

From the source code of the application we know that the function sum() from MainActivity is being run every second. Lets try to dump all possible information each time the function is called (arguments, return value and backtrace):

    android hooking watch class_method asvid.github.io.fridaapp.MainActivity.sum --dump-args --dump-backtrace --dump-return

#### Hooking (watching) an entire class

Actually I find all the methods of the class MainActivity really interesting, lets hook them all. Be careful, this could crash an application.

    android hooking watch class asvid.github.io.fridaapp.MainActivity --dump-args --dump-return

If you play with the application while the class is hooked you will see when each function is being called, its arguments and the return value.

#### Changing boolean return value of a function

From the source code you can see that the function checkPin gets a String as argument and returns a boolean. Lets make the function always return true:

Now, If you write anything in the text box for the PIN code you will see tat anything is valid:

### Class instances

Search for and print live instances of a specific Java class, specified by a fully qualified class name. Out is the result of an attempt at getting a string value for a discovered objection which would typically contain property values for the object.

    android heap print_instances <class>

### Keystore/Intents

You can play with the keystore and intents using:

    android keystore list
    android intents launch_activity
    android intent launch_service

### Memory

#### Dump

    memory dump all <local destination> #Dump all memory
    memory dump from_base <base_address> <size_to_dump> <local_destination> #Dump a part

#### List

    memory list modules

At the bottom os the list you can see frida:

Lets checks what is frida exporting:

#### Search/Write

You can alse search and write inside memory with objection:

    memory search "<pattern eg: 41 41 41 ?? 41>" (--string) (--offsets-only)
    memory write "<address>" "<pattern eg: 41 41 41 41>" (--string)

### SQLite

You cals can use the command `sqlite` to interact with sqlite databases.

### Exit

    exit

## What I miss in Objection

- The hooking methods sometimes crashes the application (this is also because of Frida).
- You can't use the instaces of the classes to call functions of the instance. And you can't create new instances of classes and use them to call functions.
- There isn't a shortcut (like the one for sslpinnin) to hook all the common crypto methods being used by the application to see cyphered text, plain text, keys, IVs and algorithms used.

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> Support HackTricks
> - Check the subscription plans!
> - Join the 💬 Discord group or the telegram group or follow us on Twitter 🐦 @hacktricks_live.
> - Share hacking tricks by submitting PRs to the HackTricks and HackTricks Cloud github repos.