# AVD - Android Virtual Device Thank you very much to [**@offsecjay**](https://twitter.com/offsecjay) for his help while creating this content. ## What is Android Studio allows to **run virtual machines of Android that you can use to test APKs**. In order to use them you will need: * The **Android SDK tools** - [Download here](https://developer.android.com/studio/releases/sdk-tools). * Or **Android Studio** \(with Android SDK tools\) - [Download here](https://developer.android.com/studio). In Windows \(in my case\) **after installing Android Studio** I had the **SDK Tools installed in**: `C:\Users\\AppData\Local\Android\Sdk\tools` ## JDK For MacOS machines I recommend you to install the following version to be able to use the CLI commands mentioned in the following sections: ```bash brew install openjdk@8 ``` ## GUI ### Prepare Virtual Machine If you installed Android Studio, you can just open the main project view and access: _**Tools**_ --> _**AVD Manager.**_ ![](../../.gitbook/assets/image%20%28366%29.png) Then, click on _**Create Virtual Device**_, _**select** the phone you want to use_ and click on _**Next.**_ In the current view you are going to be able to **select and download the Android image** that the phone is going to run: ![](../../.gitbook/assets/image%20%28369%29.png) So, select it and click on _**Download**_ **\(**now wait until the image is downloaded\). Once the image is downloaded, just select _**Next**_ and _**Finish**_. ![](../../.gitbook/assets/image%20%28361%29.png) The virtual machine will be created. Now **every time that you access AVD manager it will be present**. ### Run Virtual Machine In order to **run** it just press the _**Start button**_. ![](../../.gitbook/assets/image%20%28364%29.png) ## Command Line tool ### Prepare Virtual Machine {% hint style="info" %} In **MacOS** systems the executable is located in `/Users//Library/Android/sdk/tools/bin` {% endhint %} First of all you need to **decide which phone you want to use**, in order to see the list of possible phones execute: ```text C:\Users\\AppData\Local\Android\Sdk\tools\bin\avdmanager.bat list device id: 0 or "tv_1080p" Name: Android TV (1080p) OEM : Google Tag : android-tv --------- id: 1 or "tv_720p" Name: Android TV (720p) OEM : Google Tag : android-tv --------- id: 2 or "wear_round" Name: Android Wear Round OEM : Google Tag : android-wear --------- id: 3 or "wear_round_chin_320_290" Name: Android Wear Round Chin OEM : Google Tag : android-wear --------- id: 4 or "wear_square" Name: Android Wear Square OEM : Google Tag : android-wear --------- id: 5 or "Galaxy Nexus" Name: Galaxy Nexus OEM : Google --------- id: 6 or "Nexus 10" Name: Nexus 10 OEM : Google --------- id: 7 or "Nexus 4" Name: Nexus 4 OEM : Google --------- id: 8 or "Nexus 5" Name: Nexus 5 OEM : Google --------- id: 9 or "Nexus 5X" Name: Nexus 5X OEM : Google ``` Once you have decide the name of the device you want to use, you need to **decide which Android image you want to run in this device.** You can list all the options using `sdkmanager`: ```bash C:\Users\\AppData\Local\Android\Sdk\tools\bin\sdkmanager.bat --list ``` And **download** the one \(or all\) you want to use with: ```bash C:\Users\\AppData\Local\Android\Sdk\tools\bin\sdkmanager.bat "platforms;android-28" "system-images;android-28;google_apis;x86_64" ``` Once you have downloaded the Android image you want to use you can **list all the downloaded Android images** with: ```text C:\Users\\AppData\Local\Android\Sdk\tools\bin\avdmanager.bat list target ---------- id: 1 or "android-28" Name: Android API 28 Type: Platform API level: 28 Revision: 6 ---------- id: 2 or "android-29" Name: Android API 29 Type: Platform API level: 29 Revision: 4 ``` At this moment you have decided the device you want to use and you have downloaded the Android image, so **you can create the virtual machine using**: ```bash C:\Users\\AppData\Local\Android\Sdk\tools\bin\avdmanager.bat -v create avd -k "system-images;android-28;google_apis;x86_64" -n "AVD9" -d "Nexus 5X" ``` In the last command **I created a VM named** "_AVD9_" using the **device** "_Nexus 5X_" and the **Android image** "_system-images;android-28;google\_apis;x86\_64_". Now you can **list the virtual machines** you have created with: ```bash C:\Users\\AppData\Local\Android\Sdk\tools\bin\avdmanager.bat list avd Name: AVD9 Device: Nexus 5X (Google) Path: C:\Users\cpolo\.android\avd\AVD9.avd Target: Google APIs (Google Inc.) Based on: Android API 28 Tag/ABI: google_apis/x86_64 The following Android Virtual Devices could not be loaded: Name: Pixel_2_API_27 Path: C:\Users\cpolo\.android\avd\Pixel_2_API_27_1.avd Error: Google pixel_2 no longer exists as a device ``` ### Run Virtual Machine We have already seen how you can list the created virtual machines, but **you can also list them using**: ```bash C:\Users\\AppData\Local\Android\Sdk\tools\emulator.exe -list-avds AVD9 Pixel_2_API_27 ``` You can simply **run any virtual machine created** using: ```bash C:\Users\\AppData\Local\Android\Sdk\tools\emulator.exe -avd "VirtualMachineName" C:\Users\\AppData\Local\Android\Sdk\tools\emulator.exe -avd "AVD9" ``` Or using more advance options you can run a virtual machine like: ```bash C:\Users\\AppData\Local\Android\Sdk\tools\emulator.exe -avd "AVD9" -http-proxy 192.168.1.12:8080 -writable-system ``` ### Command line options However there are **a lot of different command line useful options** that you can use to initiate a virtual machine. Below you can find some interesting options but can ****[**find a complete list here**](https://developer.android.com/studio/run/emulator-commandline) #### Boot * `-snapshot name` : Start VM snapshot * `-snapshot-list -snapstorage ~/.android/avd/Nexus_5X_API_23.avd/snapshots-test.img` : List all the snapshots recorded #### Network * `-dns-server 192.0.2.0, 192.0.2.255` : Allow to indicate comma separated the DNS servers to the VM. * **`-http-proxy 192.168.1.12:8080`** : Allow to indicate an HTTP proxy to use \(very useful to capture the traffic using Burp\) * `-port 5556` : Set the TCP port number that's used for the console and adb. * `-ports 5556,5559` : Set the TCP ports used for the console and adb. * **`-tcpdump /path/dumpfile.cap`** : Capture all the traffic in a file #### System * `-selinux {disabled|permissive}` : Set the Security-Enhanced Linux security module to either disabled or permissive mode on a Linux operating system. * `-timezone Europe/Paris` : Set the timezone for the virtual device * `-screen {touch(default)|multi-touch|o-touch}` : Set emulated touch screen mode. * **`-writable-system`** : Use this option to have a writable system image during your emulation session. You will need also to run `adb root; adb remount`. This is very useful to install a new certificate in the system. ## Install Burp certificate on a Virtual Machine First of all you need to download the Der certificate from Burp. You can do this in _**Proxy**_ --> _**Options**_ --> _**Import / Export CA certificate**_ ![](../../.gitbook/assets/image%20%28367%29%20%281%29.png) **Export the certificate in Der format** and lets **transform** it to a form that **Android** is going to be able to **understand.** Note that **in order to configure the burp certificate on the Android machine in AVD** you need to **run** this machine **with** the **`-writable-system`** option. For example you can run it like: ```bash C:\Users\\AppData\Local\Android\Sdk\tools\emulator.exe -avd "AVD9" -http-proxy 192.168.1.12:8080 -writable-system ``` Then, to **configure burps certificate do**: ```bash openssl x509 -inform DER -in burp_cacert.der -out burp_cacert.pem CERTHASHNAME="`openssl x509 -inform PEM -subject_hash_old -in burp_cacert.pem | head -1`.0" mv burp_cacert.pem $CERTHASHNAME #Correct name adb root && adb remount #Allow to write on /syste adb push $CERTHASHNAME /sdcard/ #Upload certificate adb shell mv /sdcard/$CERTHASHNAME /system/etc/security/cacerts/ #Move to correct location adb shell chmod 644 /system/etc/security/cacerts/$CERTHASHNAME #Assign privileges adb reboot #Now, reboot the machine ``` Once the **machine finish rebooting** the burp certificate will be in use by it! ## Take a Snapshot You can **use the GUI** to take a snapshot of the VM at any time: ![](../../.gitbook/assets/image%20%28363%29.png)