Patching Android ARM64 library initializers for easy Frida instrumentation and debugging

Intro During both mobile security and mobile resiliency assessments, you often end up instrumenting the application to analyze its internals. By using either Frida or a classical debugger, we can gain valuable insight into the data flows and also modify some data on the fly to make the application behave the way we want it … Continue reading Patching Android ARM64 library initializers for easy Frida instrumentation and debugging →

Intercepting traffic on Android with Mainline and Conscrypt

TL;DR: The AlwaysTrustUserCerts module now supports Android 7 until Android 16 Beta. If you want to learn more about Mainline, Conscrypt and how everything works together, keep reading! Intro To properly test the backend of any mobile application, we need to intercept (and modify) the API traffic. We could use Swagger or Postman files if … Continue reading Intercepting traffic on Android with Mainline and Conscrypt →

Unpacking Flutter hives

Intro When analyzing the security of mobile applications, it's important to verify that all data is stored securely (See OWASP MASVS-STORAGE-1). A recent engagement involved a Flutter app that uses the Isar/Hive framework to store data. The engagement was unfortunately blackbox, so we did not have access to any of the source code. This especially … Continue reading Unpacking Flutter hives →

Deobfuscating Android ARM64 strings with Ghidra: Emulating, Patching, and Automating

In a recent engagement I had to deal with some custom encrypted strings inside an Android ARM64 app. I had a lot of fun reversing the app and in the process I learned a few cool new techniques which are discussed in this writeup. This is mostly a beginner guide which explains step-by-step how you … Continue reading Deobfuscating Android ARM64 strings with Ghidra: Emulating, Patching, and Automating →

Intercept Flutter traffic on iOS and Android (HTTP/HTTPS/Dio Pinning)

Some time ago I wrote some articles on how to Man-In-The-Middle Flutter on iOS, Android (ARM) and Android (ARM64). Those posts were quite popular and I often went back to copy those scripts myself. Last week, however, we received a Flutter application where the script wouldn't work anymore. As we had the source code, it … Continue reading Intercept Flutter traffic on iOS and Android (HTTP/HTTPS/Dio Pinning) →

New mobile malware family now also targets Belgian financial apps

While banking trojans have been around for a very long time now, we have never seen a mobile malware family attack the applications of Belgian financial institutions. Until today... Earlier this week, the Italy-based Cleafy published an article about a new android malware family which they dubbed TeaBot. The sample we will take a look … Continue reading New mobile malware family now also targets Belgian financial apps →