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Visual Basic 6 アプリケーションの逆コンパイル、コード復元、保守に関する技術記事。
VB6 application support: what actually breaks, and what does not
The application still runs after twenty years, and that is not luck: Microsoft supports the runtime for the lifetime of every Windows release. What gives way is elsewhere — and it is almost never the language.
A history of Visual Basic decompilers, from VBDis to today
Thirty years of Visual Basic reverse engineering tooling: the eleven known tools, their authors, their dates, and the community that documented a format Microsoft never published.
A history of Visual Basic: how Ruby and Embedded Basic merged in 1991
Visual Basic is the assembly of two unrelated projects: a form generator bought from Alan Cooper and a Basic engine written for a database. Their marriage was decided by a Bill Gates memo in August 1989 — and the seam is still legible in the executables.
VB6 decompiler or disassembler: which one do you need?
A disassembler shows you the instructions; a decompiler tries to reconstruct the source. Both outputs on the same procedure, and how to choose according to what you are trying to obtain.
From P-Code to MSIL: the history of Visual Basic told through its binaries
Visual Basic produced three binary formats in thirty years. Each decides what decompilation can give back — and explains why reading a .NET assembly is free while rebuilding a VB6 executable is not.
Analysing VB6 malware: our partnership with Malva.RE
Malva.RE uses VBReFormer to decompile malicious Visual Basic 6 binaries. Why native VB6 code remains a blind spot for modern tooling, and what decompilation actually changes for an analyst.
Free and open-source .NET decompilers: which one to use
VBReFormer handles Visual Basic 5 and 6, not .NET, and .NET is not planned for any future version. If you need to decompile a .NET assembly, these are the tools that do it — all free, most of them open source.
Why malware campaigns keep coming back to Visual Basic 6
A 1998 language at the heart of 2025 attacks: Visual Basic 6 is enjoying an unexpected second life among malware authors. A look at the technical reasons and the recent campaigns.
Running a VB6 application on Windows 10 and 11
Good news: the Visual Basic 6 runtime is still supported on Windows 10 and 11. Here's what works, what breaks, and what to do when an application refuses to start.
Migrating a VB6 application to .NET: where to start
Modernizing a Visual Basic 6 application to .NET is a project in its own right. Here are the key steps, the classic pitfalls, and the role decompilation plays when the source code is missing.
Lost VB6 source code: how to recover it from the executable
The developer has left, the server was reinstalled, the backup is corrupt — but the application still runs. What exactly comes back from the .exe alone, and what does not.
Decompile P-Code or native code: what your VB6 binary gives back
A VB6 executable was compiled one of two ways, and what decompilation yields depends entirely on which. The mode is written in the file, and each gives back something different.
Case study: decompiling a VB6 CrackMe to understand its algorithm
A hands-on reverse engineering exercise: how decompiling a Visual Basic 6 binary reveals the logic behind its validation key.
Modifying a compiled Visual Basic 6 application without the source code
Changing a label, an image or an interface property directly inside a VB6 executable, without ever having the original source files. Why it works, and where the boundary lies.