Info Obfuscated methods

Description

Obfuscation refers to methods to obscure code and make it hard to understand. Compiled Java classes can be decompiled if there is no obfuscation during compilation step.

Adversaries can steal code and repurpose it and sell it in a new application or create a malicious fake application based on the initial one.

Code obfuscation only slows the attacker from reverse engineering but does not make it impossible.

Recommendation

Design the application to add the following protections and slow reverse engineering of the application:

  • Obfuscate Java source code with tools like Proguard or Dexguard
  • buildTypes {
            release {
                minifyEnabled true
                proguardFiles getDefaultProguardFile('proguard-android.txt'),
                'proguard-rules.pro'
            }
        }
  • Verification application signing certificate during runtime by checking context.getPackageManager().signature
  • Check application installer to ensure it matches the Android Market by calling context.getPackageManager().getInstallerPackageName
  • Check running environment at runtime
  • private static String getSystemProperty(String name) throws Exception {
        Class systemPropertyClazz = Class.forName("android.os.SystemProperties");
        return (String) systemPropertyClazz.getMethod("get", new Class[] { String.class }).invoke(systemPropertyClazz, new Object[] { name });
    }
    
    public static boolean checkEmulator() {
    
        try {
            boolean goldfish = getSystemProperty("ro.hardware").contains("goldfish");
            boolean qemu = getSystemProperty("ro.kernel.qemu").length() > 0;
            boolean sdk = getSystemProperty("ro.product.model").equals("sdk");
    
            if (qemu || goldfish || sdk) {
                return true;
            }
    
        } catch (Exception e) {
        }
    
        return false;
      }
  • Check debug flag at runtime
  • context.getApplicationInfo().applicationInfo.flags & ApplicationInfo.FLAG_DEBUGGABLE;

Technical details
PackageObfuscated
android.support.customtabs False
com.karumi.dexter False
android.support.coreutils False
android.support.transition False
android.support.annotation False
belka.us.androidtoggleswitch False
com.skyfishjy.library False
android.support.multidex False
com.comix.overwatch False
android.support.mediacompat False
android.support.design False
android.support.compat False
android.support.v4 False
steelkiwi.com.library False
com.tt.whorlviewlibrary False
com.daimajia.numberprogressbar False
com.google.ads True
android.arch.core False
android.support.fragment False
com.bumptech.glide False
org.jetbrains.annotations False
android.arch.lifecycle False
com.steelkiwi.library False
android.support.coreui False
kotlin False
com.cleveroad.androidmanimation False
com.recoverimages.datarestorepicturecanfreeapp True
com.google.firebase False