Now the AVD has to be configured in such a way that traffic from the device goes through the proxy:
Navigate to Home | Menu | Settings | Wireless & networks | Mobile Networks |Access Point Names.
Here we will configure the following proxy settings:
Proxy
Port
The following figure shows the IP address of the workstation. This is required to configure the AVD:
Enter the IP address of the system here:
After entering the IP address of the system, enter the port number, 8080, as shown here:
Once this is done, all the HTTP traffic from the device will be sent via the Burp proxy on your machine. We will make use of this setup extensively when we discuss weak server-side controls.
Drozer is a tool used for automated Android app assessments. The following are the steps to get Drozer up and running.
Following are the requirements for setting up:
A workstation (in my case Windows 7) with the following:
JRE or JDK
Android SDK
An Android device or emulator running Android 2.1 or later.
First, grab a copy of the Drozer installer and
Agent.apk
from the following link:https://www.mwrinfosecurity.com/products/drozer/community-edition/
Download the appropriate version of Drozer if you are working with a different setup than what we are using in this book.
After downloading, run the Drozer installer. Installation uses the usual Windows installation wizard, as shown here:
Click Next and choose the destination location for Drozer installation:
As shown in the preceding screenshot, the default location is
C:\drozer
. It is recommended you use the default location if you would like to configure your system identical to ours. Follow the wizard's instructions to complete the installation. The installation window is shown in the following screenshot for your reference:
The preceding installation process automatically installs all the required Python dependencies and sets up a complete Python environment.
To check the validity of the installation, perform the following steps:
Start a new command prompt and run the
drozer.bat
file, as shown in the following screenshot:Now, install the
agent.apk
file we downloaded earlier onto your emulator. We can install.apk
files using theadb
command:adb install agent.apk
To start working with Drozer for your assessments, we need to connect the Drozer console on the workstation to the agent on the emulator. To do this, start the agent on your emulator and run the following command to port forward. Make sure you are running the embedded server when launching the agent.
adb forward tcp:31415 tcp:31415
As we can see, the command completed successfully without any errors:
Now, we can simply run the following command to connect to the agent from the workstation:
[path to drozer dir]\drozer.bat console connect
We should now be presented with the Drozer console, as shown here:
According to their official GitHub page, QARK is an easy-to-use tool capable of finding common security vulnerabilities in Android applications. Unlike commercial products, it is 100% free to use. QARK features educational information allowing security reviewers to locate precise, in-depth explanations of vulnerabilities. QARK automates the use of multiple decompilers, leveraging their combined outputs to produce superior results when decompiling APKs.
QARK uses static analysis techniques to find vulnerabilities in Android apps and source code.
As of writing this, QARK only supports Linux and Mac:
This will launch an interactive QARK console, shown in the following screenshot:
Advanced REST Client is an add-on for Chrome. This is useful for penetration testing REST APIs, which are often a part of mobile applications:
Install the Google Chrome browser.
Open the following URL:
Search for Advanced REST client. You should see the following Chrome extension. Click the ADD TO CHROME button to add it to your browser:
It will prompt you for your confirmation, as shown in the following screenshot:
Once you are done adding this extension to Google Chrome, you should have the add-on available, as shown here:
Most of the time in this book, we will use command line tools to explore the Android filesystem, pulling/pushing data from/to the device. If you are a GUI lover, you will appreciate using Droid Explorer, a GUI tool to explore the Android filesystem on rooted devices.
Droid Explorer can be downloaded from the following link:
Introspy is a blackbox tool which helps us to understand what an Android application is doing at runtime, and enables us to identify potential security issues.
Introspy Android consists of two modules:
Follow this process to set up Introspy:
Download Introspy Analyzer from the following link:
Installing Cydia Substrate for Android is a requirement in order to successfully install Introspy. Let's download it from the Android Play Store and install it:
Now, install Introspy-Android Config.apk and Introspy-Android Core.apk, which we downloaded in step 1. These are the commands to install them using
adb
:adb install Introspy-Android Config.apk adb install Introspy-Android Core.apk
You should see the following icons if the installation was successful:
We often come across SQLite databases when dealing with Android applications. SQLite browser is a tool that can be used to connect to SQLite databases. It allows us to perform database operations using some eye candy:
Frida is a framework developed for the dynamic instrumentation of apps on various platforms, which includes support for Android, iOS, Windows and Mac. This tool helps us hook into the apps and performs runtime manipulation.
Some important links are as follows:
https://github.com/frida/frida
http://www.frida.re/docs/android/
The following section shows how to set up Frida. We have used a Mac in this example.
Prerequisites:
Frida client: This will be running on the workstation
Frida server: This will be running on the device
Download Frida server onto your local machine using the following command:
curl -O http://build.frida.re/frida/android/arm/bin/frida-server $ curl -O http://build.frida.re/frida/android/arm/bin/frida-server % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 100 12.0M 100 12.0M 0 0 232k 0 0:00:53 0:00:53 --:--:-- 166k $
This step should download the frida-server binary to the workstation and into the current directory.
Give Frida server execute permissions using the following command:
chmod +x frida-server
Push the frida-server binary to the device using
adb push
, as shown here:$ adb push frida-server /data/local/tmp/
Now, get a shell on the device with root privileges and run frida-server as shown here:
$ adb shell shell@android:/ $ su root@android:/ # cd /data/local/tmp root@android:/data/local/tmp # ./frida-server & [1] 5376 root@android:/data/local/tmp #
Installing frida-client is as simple as issuing the following command:
$ sudo pip install frida Password: Downloading/unpacking frida Downloading frida-5.0.10.zip Running setup.py (path:/private/tmp/pip_build_root/frida/setup.py) egg_info for package frida Downloading/unpacking colorama>=0.2.7 (from frida) Downloading colorama-0.3.3.tar.gz Running setup.py (path:/private/tmp/pip_build_root/colorama/setup.py) egg_info for package colorama Downloading/unpacking prompt-toolkit>=0.38 (from frida) Downloading prompt_toolkit-0.53-py2-none-any.whl (188kB): 188kB downloaded Downloading/unpacking pygments>=2.0.2 (from frida) Downloading Pygments-2.0.2-py2-none-any.whl (672kB): 672kB downloaded Requirement already satisfied (use --upgrade to upgrade): six>=1.9.0 in /Library/Python/2.7/site-packages/six-1.9.0-py2.7.egg (from prompt-toolkit>=0.38->frida) Downloading/unpacking wcwidth (from prompt-toolkit>=0.38->frida) Downloading wcwidth-0.1.5-py2.py3-none-any.whl Installing collected packages: frida, colorama, prompt-toolkit, pygments, wcwidth Running setup.py install for frida downloading prebuilt extension from https://pypi.python.org/packages/2.7/f/frida/frida-5.0.10-py2.7-macosx-10.11-intel.egg extracting prebuilt extension Installing frida-ls-devices script to /usr/local/bin Installing frida script to /usr/local/bin Installing frida-ps script to /usr/local/bin Installing frida-trace script to /usr/local/bin Installing frida-discover script to /usr/local/bin Running setup.py install for colorama Successfully installed frida colorama prompt-toolkit pygments wcwidth Cleaning up... $
Now the client and server are ready. We need to configure port forward with adb before we can start using them. Use the following commands to enable port forwarding:
$ adb forward tcp:27042 tcp:27042 $ adb forward tcp:27043 tcp:27043
Now, type in —help
to check the Frida client options:
$ frida-ps --help Usage: frida-ps [options] Options: --version show program's version number and exit -h, --help show this help message and exit -D ID, --device=ID connect to device with the given ID -U, --usb connect to USB device -R, --remote connect to remote device -a, --applications list only applications -i, --installed include all installed applications $
As we can see in the preceding output, we can use –R
to connect to the remote device. This acts as a basic test for testing our setup:
$ frida-ps -R PID Name ----- ---------------------------------------- 177 ATFWD-daemon 233 adbd 4722 android.process.media 174 cnd 663 com.android.phone 4430 com.android.settings 757 com.android.smspush 512 com.android.systemui . . . . . . 138 vold 2533 wpa_supplicant 158 zygote $
As we can see, a list of running processes has been listed down.
We will be using various vulnerable Android applications to showcase typical attacks on Android apps. These provide a safe and legal environment for readers to learn about Android security:
Kali Linux is a penetration testing distribution often used by security professionals to perform various security tests.
It is suggested that readers install a copy of Kali Linux in VirtualBox or VMware to prepare for network-level attacks on Android devices. Kali Linux can be downloaded from the following link: