Tamper Detection

What Is Tamper Detection?

Tamper detection refers to the process of detecting any unauthorized modifications or tampering attempts made to the code or data of a mobile application. The purpose of tamper detection is to prevent users from using a mobile app that has been tampered with. Without it, the security and privacy of app users can be compromised, leading to data breaches, theft of sensitive information, or even malicious attacks. 

Anti-tampering is used interchangeably with tamper detection.

App Tampering Methods

Performing unauthorized modifications on mobile apps can be done through various methods. Here are some common ways attackers can modify mobile apps:

1. Binary patching. Binary patching involves modifying the app's binary code directly in order to change its behavior. This can be done by modifying the app's executable file, for example, by changing its instructions or replacing its code with malicious code.
2. Code injection. Code injection involves injecting malicious code into the app to modify its behavior. Attackers can use techniques such as SQL injection or JavaScript injection to inject malicious code into the app's codebase.
3. Man-in-the-middle (MitM) attacks. MitM attacks involve intercepting the communication between the mobile app and the server it communicates with. This can allow attackers to modify the data being sent between the app and the server.
4. Method hooking. Method hooking involves intercepting the calls to a specific method in the app's code and modifying its behavior. This can be used to bypass security measures, steal data, or perform other malicious activities.
5. Reverse engineering. Reverse engineering involves analyzing the app's code to understand how it works and how it can be modified. Attackers can use tools such as decompilers and debuggers to reverse engineer an app's code and identify vulnerabilities or weak points.
6. Rooting or jailbreaking. Rooting or jailbreaking involves gaining access to the root or administrative privileges of a mobile device. This allows attackers to modify the app's code or data directly..

By exploiting these vulnerabilities, attackers can perform unauthorized modifications on mobile apps, compromising the security and privacy of the app's users.

Tamper Detection Techniques

Detecting unauthorized modifications or tampering attempts on a mobile app involves using various techniques to monitor the integrity of the app and its environment. Common anti-tampering techniques that can be used in mobile apps include:

1. Anti-debugging techniques. Anti-debugging techniques involve adding code to the app that detects and prevents debugging attempts. This can involve using code that crashes the app if it detects a debugger, or using code that detects specific debugging techniques, such as breakpoints or memory dumps.
2. Code obfuscation. Code obfuscation involves modifying the code of the app to make it more difficult to understand or modify. This can include techniques such as renaming variables and functions, adding unused code, and encrypting or hashing sensitive data.
3. Environment checks. Environment checks involve monitoring the environment in which the mobile app is running to detect any signs of tampering or unauthorized access. This can include techniques such as checking the device's settings, network connections, and other system parameters.
4. Integrity checks. Integrity checks involve verifying the integrity of the app's code and data in order to detect any unauthorized modifications. One way to do this is via checksum validation, which involves calculating checksums or digital signatures of the app's code and data, and comparing them to the expected values. If the calculated values do not match the expected values, it indicates that the app has been modified.
5. Jailbreak or root detection. Jailbreak detection (for iOS) and root detection (for Android) involves checking whether the mobile device has been rooted or jailbroken, which can indicate that the mobile app's security measures have been bypassed.
6. Tamper-proofing data. Tamper-proofing data involves encrypting and securing sensitive data in the app, in order to prevent attackers from accessing or modifying it. This can involve using encryption algorithms, secure storage mechanisms, or network communication protocols that are resistant to tampering.

By using one or more of these techniques, mobile app developers can implement tamper detection for mobile apps to protect against unauthorized modifications, data breaches, and other security threats. No single technique can provide complete protection against all types of app tampering attempts. Therefore a combination of techniques is usually needed for effective tamper detection.

Tamper detection should be part of a Mobile RASP (Runtime Application Self-Protection) solution.