What Are the Common Techniques Used in Mobile App Tampering?

Mobile app tampering refers to any unauthorised modification of an app’s code or data to change its behaviour. Attackers target apps, especially fintech, healthcare or enterprise, by statically altering their binaries or injecting code at runtime. 

In binary patching or repackaging, the attacker decompiles the app with tools like Apktool, edits the code and resources, then rebuilds and re-signs the app. It allows them to remove checks, hardcoded logics, and insert backdoors. For example, by app tampering, they could remove an OTP check or expose encrypted data. 

Common techniques used in mobile app tampering are:

• Reverse engineering

Before an attacker can tamper with an app, they must understand its blueprints. Using tools like JADX or Ghidra, attackers decompile binaries into readable code. This reveals hardcoded API keys, algorithms, and weak links. 

• Dynamic binary instrumentation or DBI (hooking)

The most common technique to hook an app is DBI. It uses a framework like Frida to hook into a running app and intercept function calls in real-time. This bypass checks and redirects an API call to a malicious server.

• Repackaging and code injection

In this technique, attackers decompile the APK/IPA file and inject malicious code into it, recompile it and re-sign it with a fake certificate. These cloned apps are distributed through third-party app stores, and people download them assuming it as the legit app. 

• Bypass system protections

Attackers hide their presence with sophisticated tampering scripts. They use anti-anti-tamper logic to perform:

• Spoof Jailbreak/root status.

• Disable SSL pinning.

• Hooking authentication methods, forcing it to return ‘True’, regardless of the password provided and bypassing the logic gates.

To combat this, runtime application self-protection (RASP) solutions add anti-tampering checks at runtime. Bugsmirror Defender embeds runtime checks into the app that monitor threats like mobile app tampering and others. It protects apps against more than 50 runtime threats.

Meanwhile, Bugsmirror Shield applies code hardening, which virtualises native code into proprietary opcodes and encrypts critical strings. Together, these defences help ensure that tampering attempts are prevented or rendered ineffective.

The first step to secure a mobile app is to identify its strengths against threats. What is better than a free audit of runtime threats? Contact us now!