Tool

GUI

Application Security

bytecode-viewer

by Konloch

15.0Kstars

1.2Kforks

375watchers

Updated 10 months ago

About

Bytecode Viewer is a lightweight, user-friendly Java and Android reverse engineering suite featuring multiple decompilers, editors, and debugging tools.

A Java 8+ Jar & Android APK Reverse Engineering Suite (Decompiler, Editor, Debugger & More)

Primary Use Case

This tool is primarily used by security researchers, malware analysts, and developers to reverse engineer Java and Android applications by decompiling, editing, and analyzing bytecode and APK files. It facilitates malware analysis, exploitation research, and security automation by providing an integrated environment for static code inspection and modification.

Key Features

Supports drag and drop decompilation of Java Jars and Android APKs
Includes 6 built-in Java decompilers (Krakatau, CFR, Procyon, FernFlower, JADX, JD-GUI)
Features 3 bytecode disassemblers and 2 assemblers (Krakatau, Smali/BakSmali)
Supports multiple file formats including Class, Jar, APK, DEX, WAR, JSP, and more
Built-in Java compiler and advanced static search functionality
Plugin and script engine support with a plugin console
Malicious code scanning API integrated
Multi-language support with dark mode and customizable UI

Installation

Download the latest release from https://github.com/konloch/bytecode-viewer/releases
Run the downloaded JAR file using the command: java -jar Bytecode-Viewer-2.10.x.jar
Replace '2.10.x' with the current minor version number as needed

Usage

>_ -help

Displays the help menu

>_ -clean

Deletes the BCV directory

>_ -english

Forces English language translations

>_ -list

Displays the available decompilers

>_ -decompiler <decompiler>

Selects the decompiler to use, default is Procyon

>_ -i <input file>

Specifies the input file (Jar, Class, APK, ZIP, DEX supported automatically)

>_ -o <output file>

Specifies the output file (Java source or Java bytecode)

>_ -t <target classname>

Specifies the fully qualified classname to decompile or 'all' to decompile all as zip

>_ -nowait

Does not wait for user input before closing CLI messages

Security Frameworks

Reconnaissance

Resource Development

Initial Access

Execution

Defense Evasion

Usage Insights

Integrate Bytecode Viewer with automated malware sandbox environments to enhance static analysis capabilities.
Use the plugin and scripting engine to develop custom detection rules for identifying obfuscated or malicious Java/Android code.
Leverage multi-decompiler support to cross-verify suspicious code segments and improve reverse engineering accuracy.
Incorporate Bytecode Viewer into red team toolkits for rapid exploit development and payload customization targeting Java-based applications.
Deploy as part of purple team exercises to bridge gaps between offensive code analysis and defensive signature creation.

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Security Profile

Red Team85%

Blue Team35%

Purple Team60%

Details

LicenseGNU General Public License v3.0

LanguageJava

Open Issues361

Topics

java-decompiler

apk