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

How to analyze mobile malware: a Cabassous/FluBot Case study

This blogpost explains all the steps I took while analyzing the Cabassous/FluBot malware. I wrote this while analyzing the sample and I've written down both successful and failed attempts at moving forward, as well as my thoughts/options along the way. As a result, this blogpost is not a writeup of the Cabassous/FluBot malware, but rather … Continue reading How to analyze mobile malware: a Cabassous/FluBot Case study

Proxying Android app traffic – Common issues / checklist (2023)

Latest update: February 2023 During a mobile assessment, there will typically be two sub-assessments: The mobile frontend, and the backend API. In order to examine the security of the API, you will either need extensive documentation such as Swagger or Postman files, or you can let the mobile application generate all the traffic for you … Continue reading Proxying Android app traffic – Common issues / checklist (2023)

Intercepting Flutter traffic on iOS

My previous blogposts explained how to intercept Flutter traffic on Android ARMv8, with a detailed follow along guide for ARMv7. This blogpost does the same for iOS. ⚠️ Update August 2022 ⚠️An update to this blog post was written and can be found here. It covers both iOS and Android and a convenient script / … Continue reading Intercepting Flutter traffic on iOS

Intercepting Flutter traffic on Android (ARMv8)

In a previous blogpost, I explained my steps for reversing the flutter.so binary to identify the correct offset/pattern to bypass certificate validation. As a very quick summary: Flutter doesn't use the system's proxy settings, and it doesn't use the system's certificate store, so normal approaches don't work. My previous guide only explained how to intercept … Continue reading Intercepting Flutter traffic on Android (ARMv8)