Mobile Application Security: Practical Notes and Challenge Solutions

During the past period, I focused heavily on Mobile Application Security, covering fundamentals and advanced techniques. I completed several challenges, primarily from hextree.io and MobileHackingLabs, and documented my solutions and notes on GitHub. Below are the key resources:

• Mobile Security Notes: https://lnkd.in/dnUsv2XQ
• Challenge Solutions: https://lnkd.in/dcKeFvC9
• MobileHackingLabs Challenge: https://lnkd.in/dBSvzr4v

You Should Know:

1. Static Analysis with `apktool` and `jadx`

• Decompile an APK for static analysis:

  apktool d target.apk -o output_dir
  jadx --show-bad-code target.apk -d decompiled_java
  

2. Dynamic Analysis with Frida

• Hook a method in a mobile app:

  // frida_script.js
  Java.perform(function() {
  let targetClass = Java.use("com.example.vulnapp.MainActivity");
  targetClass.login.implementation = function(user, pass) {
  console.log("Intercepted login: " + user + ":" + pass);
  return this.login(user, pass);
  };
  });
  

Run with:

frida -U -l frida_script.js -f com.example.vulnapp --no-pause

3. Bypassing SSL Pinning

• Use objection to disable SSL pinning:

  objection -g com.example.app explore --startup-command "android sslpinning disable"
  

4. Root Detection Evasion

• Patch root checks in smali code:

  </li>
  </ul>
  
  <h1>Change "return v0" (1 = true) to "const/4 v0, 0x0" (false)</h1>
  
  const/4 v0, 0x0
  return v0
  

  5. Automated Scanning with MobSF

  • Run Mobile Security Framework:

    docker run -it --rm -p 8000:8000 opensecurity/mobile-security-framework-mobsf
    

  What Undercode Say:

  Mobile app security requires both static and dynamic analysis. Tools like Frida, objection, and MobSF streamline testing, while manual smali patching helps bypass protections. Always document findings for reproducibility.

  Expected Output:

  • Decompiled APK code.
  • Frida hooks intercepting sensitive data.
  • Patched APK bypassing root/SSL checks.
  • MobSF report detailing vulnerabilities.

  *(End of )*

  References:

  Reported By: 0xheg3zy %D8%A7%D9%84%D8%B3%D9%84%D8%A7%D9%85 – Hackers Feeds
  Extra Hub: Undercode MoN
  Basic Verification: Pass ✅

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