Activity 3

                                                                                  Estimated Time: 15 Minutes

↠1.1 Objective

In this Activity 3, a new APK file is built with modified code and signed with key store file.

↠1.2 Description

With malicious code injected into one of the files of APK in Activity 2, we will re-build the APK file now and sign it with same java key store file generated during Activity1.

↠1.3 Prerequisites

For this Activity you need to download, install jdk and set environment variables 'Path' & 'JAVA_HOME' in windows. This is required for running 'jarsigner' command to build the modified APK file. You can watch below YouTube video for reference.
How to Install Java JDK 18 on Windows 10

↠1.4 Artifacts

Click below link to download modified APK file
login.apk

↠1.5 Instructions

Step 1: After updating code of "RestClient.smali" file in Activity 2, we will re-build app-release.apk file in this Activity.

Step 2: Open command prompt and go to path where you have placed files "app-release.apk" & "apktool_2.0.0rc3.jar" initially.

Step 3: Execute below command to build app-release folder and create new "app-release.apk" file.

Step 4: Observe that a new file "app-release.apk" is created under sub-folder /app-release/dist/

Step 5: Since the code has changed, old signature is invalid. So, we need to sign it again.

Step 6: Open command prompt and execute below command.

Step 7: To save time, modified APK file with name as "login.apk" is provided under "Activity 3: Artifacts" section. Kindly use it for subsequent Activities

↠1.6★ ★ ★ Self-Assessment ★ ★ ★

Please complete the following self-assessment over Activity 3

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↠1.7 Activity 3 - Feedback 😍😁😶🙁😞

Please complete the following survey questions over Activity 3

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