[TOOL] Adding hermes-dec as a general tool for React Native static analysis

tools/generic/MASTG-TOOL-0104.md

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+---
+title: hermes-dec
+platform: generic
+source: https://github.com/P1sec/hermes-dec/
+---
+
+[Hermes-dec](https://github.com/P1sec/hermes-dec/) is a tool for reverse-engineering compiled [hermes](https://reactnative.dev/docs/hermes) bytecode for both Android and iOS apps. It supports decompilation and disassembly of [Hermes VM bytecode (HBC)](https://lucasbaizer2.github.io/hasmer/hasm/instruction-docs/hbc86.html) format, typically seen in apps developed in [React Native](https://reactnative.dev/).
+
+If you encounter either of the following files during static analysis, hermes-dec provides a way to recover a legible version of the file's contents:
+- index.android.bundle
+- main.jsbundle
+
+Use file to check the type and confirm you are dealing with actual Hermes bytecode:
+```bash
+file main.jsbundle
+main.jsbundle: Hermes JavaScript bytecode, version 90
+```
+If instead you see that its a plain text file, it can likely just be opened with any text editor and hermes-dec isn't needed:
+```bash
+file main.jsbundle
+main.jsbundle: Unicode text, UTF-8 text
+```
+
+You can try using hermes-dec in situations where you are doing static analysis on a React Native mobile app, and [react-native-decompiler](https://github.com/numandev1/react-native-decompiler) fails.
+
+