This will walk you through setup for WeChat mobile app on Android (for either an emulated or rooted device), and setup for both Wireshark and Frida instrumentation for analysis.
- ADB setup For emulation: Android Studio, create new image of Pixel 5 API 32 with at least 5GB internal storage, optionally more in SD card if you’d like.
brew install android-platform-tools
If using real device, make sure device is rooted, connect using USB.
adb devices should list either the emulated or the rooted device.
Run adb root.
2. WeChat setup
Download Wechat APK compiled form arm64-v8a / armeabi-v7a (assuming wechat.apk) from the official version list.
We are looking at version 8.0.23 / 2160 APK, fetched from https://dldir1.qq.com/weixin/android/weixin8023android2160_arm64_1.apk.
apk install wechat.apk
- Network inspection setup tcpdump should already be installed on the Android device if the version is recent. Similarly, on the host device, if android-platform-tools is installed then androiddump should be installed as well. On host computer, ensure “tshark -D” lists an android interface. For an emulator this should be something like “android-tcpdump-any-emulator-5554”. You should then be able to sniff all traffic on the Android device with Wireshark by selecting this interface.
- Frida setup Frida docs for Android Download frida-server for the correct architecture of your emulated or real device (in my case, android-arm64)
pip3 install frida-tools
adb push frida-server /data/local/tmp/
adb shell "chmod 755 /data/local/tmp/frida-server"
adb shell "/data/local/tmp/frida-server &"
- Putting it all together To test to make sure it is working, on host, type:
frida-trace -U -i “Java_com_tencent_mm_protocal_*” WeChat
Then on the WeChat application, change the application language (this should be possible even without logging in). This will consistently generate a single MMTLS request. Frida should see a single call to
Java_com_tencent_mm_protocal_MMProtocalJni_packHybridEcdh()
Java_com_tencent_mm_protocal_MMProtocalJni_unpack()
per MMTLS request. You can verify that a single MMTLS request has occurred via Wireshark. Mobile static analysis For static analysis we are mostly using JADX and the associated GUI.
These scripts should work by running:
frida -U -f com.tencent.mm -l [frida-script].js