VB Decompiler - Advanced Visual Basic 5.0/6.0 and C# Decompilation Tool


VB Decompiler is the perfect source code recovery solution for Visual Basic 5.0/6.0, Visual Basic .NET, and Visual C# applications. Fast and powerful x86, x64 and MS IL disassemblers and decompilers for Visual Basic 5/6 and Visual Studio .NET compiled files.

Source code loss is a very serious problem for many software developers. Most Visual Basic 5.0/6.0 applications were developed years ago, and their source code (.vbp, .frm, and .bas files) has been lost due to system migrations, hard drive failures, or backup issues.

Based on the experience of our customers, losing source code can be a tragedy. Just imagine: you've spent months developing a program, but now all that remains is the compiled EXE file with DLL libraries.

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See exactly what the free Lite edition can inspect or choose a recovery workflow.

VB Decompiler native code decompiler interface showing Visual Basic 6 decompilation

Visual Basic 6.0 Source Code Recovery

Visual Basic 5.0 and 6.0 has two compilation modes: P-Code (pseudo code) and Native Code (x86 machine code). When source code is lost, each format needs a different recovery workflow:

  • P-Code: Recovers close to 85% of code in typical supported VB5/6 P-Code applications and processes COM OLE objects and API calls
  • Native Code: Powerful disassembler, code emulator, and decompiler recover up to 85% of code in typical supported VB5/6 Native Code applications. The remaining fragments require developer analysis and correction.
  • Tracing engine: Step-by-step code execution emulation for deep Native Code analysis
  • Complete form restoration - decompiles forms (frm, frx) and user controls (ctl, ctx) with all properties
  • API calls restoration - recovers prototypes of most standard Win32 APIs automatically
VB Decompiler C# switch case statement decompilation from .NET assembly

.NET and C# Decompilation

Full support for Visual Studio 2022 and earlier versions using .NET Framework or .NET Core:

  • Decompiles and disassembles Visual Basic .NET, C#, and other .NET-compatible languages
  • Restores MS IL code to C# code with high accuracy
  • Recovers code structure from assembly tables and metadata

Typical supported, non-obfuscated assemblies can be recovered up to 95%, but lost names, dependencies, compiler transformations, and unsupported fragments still require developer review before recompilation. The AI Helper can use local offline models or the OpenAI API to improve selected code. Download free Lite version to inspect .NET IL first.

VB Decompiler Analytic Report showing malware behavior analysis

Malware Analysis and Forensic Investigation

VB Decompiler is a perfect tool for cybersecurity professionals, antivirus analysts, and digital forensic experts. VB Decompiler's Analytic Features dramatically accelerate malware analysis and backdoor detection by providing instant insights into suspicious program behavior.

Automated Behavior Analysis: Get a comprehensive Analytic Report that instantly identifies which procedures and functions perform suspicious operations:

  • File system manipulation - detects procedures that create, modify, or delete files
  • Registry modifications - identifies code that changes Windows registry keys
  • Network activity - reveals procedures that download files or connect to remote servers
  • Process manipulation - shows code working with Windows processes and services
  • Memory access - detects direct memory manipulation via VarPtr and CallByName
  • Window operations - identifies procedures that hide windows or manipulate UI elements

Save weeks of manual analysis time. Instead of reading through thousands of lines of disassembled code, you immediately see a structured report highlighting all potentially malicious functions. This is invaluable for incident response teams, malware researchers, and forensic investigators working under time pressure.

Learn more about Analytic Features →

VB Decompiler P-Code decompilation result showing recovered Visual Basic source code

Professional Tools Included

  • Universal x86 unpacker - automatically unpacks UPX, NSPack, and other popular packers
  • Built-in HEX Editor - powerful binary editor with Copy/Paste and Undo/Redo
  • Syntax coloring - color-highlighted code for better readability
  • Multiple export formats - saves to MAP file, IDA script, or HIEW Names file

No dependencies required: VB Decompiler works on any supported 32-bit or 64-bit Windows system, as well as Linux systems (with Wine), without requiring .NET Framework installation.

Ready to start? Download free Lite version or purchase a license today.


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