Bypassing Root Detection, Frida Detection, and Emulator Detection in Damn Vulnerable Bank APK

In this tutorial, we will cover how to bypass root detection, Frida detection, and emulator detection in the Damn Vulnerable Bank APK. Before proceeding, ensure you have Frida installed and set up. If not, you can follow my previous guide on [automating Frida installation](https://medium.com/@r0x5r/automate-frida-installation-722171076612).

Prerequisites

• **Frida**: Ensure Frida is installed.
  - **Tools**:
  — `apktool` for decompiling and recompiling the APK.
  — `uber-apk-signer` for signing the APK.
  — `adb` for interacting with the Android device/emulator.
  — `Genymotion` for running the emulator.
  — `NotSoSecure/android_application_analyzer` for tool

Step 1: Bypass GPU Detection

Decompile the APK

apktool d com.app.damnvulnerablebank.apk -o dvb-decompiled

Modify `AndroidManifest.xml`

- Locate `AndroidManifest.xml` in the `dvb-decompiled` directory.
- Change `android:hardwareAccelerated=”true”` to `android:hardwareAccelerated=”false”`.

Recompile the APK

apktool b dvb-decompiled -o dvba-no-gpu.apk

Sign the APK

java -jar uber-apk-signer.jar - apks dvba-no-gpu.apk

Uninstall the Existing APK and Install the Modified APK

adb uninstall com.app.damnvulnerablebank
adb install dvba-no-gpu-aligned-debugSigned.apk

Step 2: Create Bypass Scripts

bypass-detection.js

setTimeout(function() {
 Java.perform(function() {
 var className = "a.a.a.a.a"; // Ensure this is the correct class name
try {
 var targetClass = Java.use(className);
 console.log('Class loaded:', className); // Confirmation that the class is loaded
if (targetClass.R) {
 var originalMethod = targetClass.R.implementation;
targetClass.R.implementation = function() {
 var originalReturnValue = this.R();
 console.log("Original return value =", originalReturnValue); // Debug for original value
return !originalReturnValue; // Negate the original return value
 };
console.log("Method 'R' has been successfully hooked.");
 } else {
 console.log("Method 'R' not found in class " + className);
 }
 } catch (e) {
 console.log("Error while trying to hook the class or method:", e);
 }
 });
}, 10);

`bypass-frida-check.js`

Java.perform(function () {
 console.log("looking for FridaCheckJNI.fridaCheck()");
try {
 const FridaCheckJNI = Java.use('com.app.damnvulnerablebank.FridaCheckJNI');
FridaCheckJNI.fridaCheck.implementation = function() {
 console.log("hooking fridaCheck().");
 var value = this.fridaCheck.call(this);
 console.log("fridaCheck() returned " + value);
 console.log("switching fridaCheck() to 0");
 return 0; // Always return 0 to bypass checks
 };
 } catch (e) {
 console.log("Failed to hook fridaCheck: " + e.message);
 }
});

Step 3: Execute Frida Scripts

Frida Server in the Emulator Device Run It

adb shell
cd  /data/local/tmp/
./frida-server &

Run the Frida Scripts this should run from main machine

frida -U -l bypass-detection.js -l bypass-frida-check.js -f com.app.damnvulnerablebank 

Reference

Mastering Mobile Security: A Guide with Damn Vulnerable Bank

you can download damn vulnerable bank by this github link

GitHub - rewanthtammana/Damn-Vulnerable-Bank: Damn Vulnerable Bank is designed to be an…

Any query DM ME

https://www.linkedin.com/in/r0x5r/

I’m also looking for a full-time job. If you know of any opportunities, please reach out!

p.s im not content writer