VBReFormer 6.4 Released with support of for/next and array-related statements decompilation

As annouced previously, we just release the Free and Professional editions of VBReFormer 6.4.

This new version improve such a lot the decompiler engine and this is one of the most important release I’ve done until now.

The decompiler engine has been improved as it can now perform variable type determination. This means that VBReFormer is now able to guess the type of a variable and argument from its use inside the code.

We also added for/next support, and multi-dimensional array-related statements decompilation.


Original source code:

Recovered source code:

Lot of other improvement has been made, here is the full details:

New: Improved support of file I/O operation statements:

  • __vbaGetOwner4
  • __vbaGetOwner3
  • __vbaGet3

New: Improved support of error statements:

  • __vbaOnError
  • __vbaResume
  • __vbaGenerateBoundsError

New: Improved support of array-related statements:

  • __vbaAryLock
  • __vbaRedim
  • __vbaRedimPreserve
  • __vbaAryConstruct2

New: Improved support of FOR / NEXT loop-related statements:

  • __vbaForEachAry
  • __vbaNextEachAry
  • __vbaExitEachAry
  • __vbaForEachCollVar
  • __vbaForEachVar
  • __vbaForEachCollAd
  • __vbaNextEachCollVar
  • __vbaNextEachCollAd
  • __vbaExitEachColl
  • __vbaExitEachVar
  • __vbaCyForInit
  • __vbaVarForInit
  • __vbaVarForNext
  • __vbaRaiseEvent
  • __vbaErase

New: Improved support of internal system statements:

  • __vbaSetSystemError
  • __vbaFreeVar
  • __vbaFreeObj
  • __vbaFreeStr
  • __vbaFreeStrList
  • __vbaFreeObjList
  • __vbaFreeVarList

New: Improved support of string statements:

  • rtcCompareBstr
  • rtcInStrChar

New: Other improved statements:

  • __vbaObjIs
  • __vbaStopExe
  • VarPtr

New: support of type consistency at decompilation time, this means that the decompiler engine can now be determinist about variable type

New: Support of OLE, PropertyPage, and UserDocument elements in GUI recovery & edition

New: Support of COM / OLE property edition


New: New settings windows that allows to:

  • edit colors of source code’s syntax highlighting


  • choose if you want only Visual Basic, assembly, or both (mixed) differently for viewing and saving
  • choose your own prefix for private method and private variable name
  • load (or not) the project in Visual Basic, or the destination folder once you saved it


Fixed issue on Import Table use

Fixed issue on Font properties in property editor and GUI edition

Fixed issue on saving settings

Fixed issue on default language setting (French was setup by default, now replaced by English language).

Fixed issue on VBReFormer setup packages for x64 Windows operating system

Fixed issue at loading some ActiveX libraries (“Run-time error 339; Component `MSCOMCT2.OCX or one of its dependencies not correctly registered. “)

Fixed issue on resource viewer

Fixed issue on re-opening a VB6 application / library previously edited with VBReFormer Pro

Fixed issue on resource image preview, export, and replacement

Fixed issue on false negative detection of VBReFormer by antivirus or browsers as malicious software

Fixed “Object not found” exception at opening some executable

Fixed “About” dialog

VBCompTester discontinued: Use VBReFormer Free Edition instead

You all know that Visual Basic 6 allows you to choose between Native Code and P-Code compilation.

Because one of the most recurrent questions of my customers was if VBReFormer Pro will support decompilation of their application, due to the simple fact they don’t know if it was compiled in Native or P-Code, I’ve made a tool called “VBCompTester”, some years ago, which show you if a binary file (.exe, .dll, .ocx, etc.) was compiled using Visual Basic 5 / 6 and with what compilation mode (native or P-Code ?).

I have also made this tools because VBReFormer Free edition was not supporting decompilation at all, while VBReFormer Pro does. Then, you were not able to know, by using the free version, if the Pro one will support your application.

But the past year I decided to make VBReFormer Free and VBReFormer Professional from the same wood in order to give a real idea of VBReFormer Professional capabilities by using the free version.

Then, since June 2014, the both version of VBReFormer, free and pro, have the same features, but limited in the case of the Free edition.

Here are the main limitation of the Free Edition:

decompilation engine will not show name of code-inside object property in Free Edition. It will show something like “Me.[PROPERTY NOT VISIBLE IN FREE EDITION]” or “Me. [METHOD NOT VISIBLE IN FREE EDITION](param1, param2, param3)” in free edition; the feature of edition of GUI interface is not supported in Free Edition.

Since the Free Edition can now be used has a demonstration version of the Professional Edition of VBReFormer, I decided to discontinue the tool VBCompTester.

You can, and I advise you to use VBReFormer Free edition in order to know if your binary is made with Native or PCode option.

If you want to know more about the difference between the both compilation modes, you can read the following article: The truth about Native Code VS P-Code.

See you very very soon with a new version of VBReFormer which is gonna be the most powerful version I have made. 🙂

VBReFormer 6.2 Released with support of Unicode System & +11000 Win32 APIs

I’m delighted to announce that we’ve released VBReFormer 6.2 Professional Edition.

New features and improvements in this release include:

– Support of Windows UNICODE settings & applications in disassembling, decompiling, and editing Visual Basic 5 & 6 applications ;

– Exclusive support of +9000 others Win32 APIs (up to a total of 11 000 APIs) ;

– Support of Left & Right properties for ActiveX / OLE related objects ;

– Support of GUI interface Font properties edition ;

– Improved support of If / Then / Else / End If, Select Case […], and Loop / While statements ;

– Improved support of GUI Code for ActiveX / OLE related objects.


This release also include major fix for issues :

– Fixed issue in saving edited Visual Basic application with UNICODE environment ;

– Fixed issue in recovering executable resource images ;

– Fixed issue in « Options » dialog, taking account of your choice about APIs related decompilation ;

– Fixed issue in adding a new property to a GUI object .

Get your Microsoft Virtualization Certification for FREE !

For a limited time you can request a free voucher to take certification exam 74-409, Microsoft Certified Specialist: Server Virtualization with Hyper-V and System Center certification for FREE.

This exam is focused on IT professionals who are responsible for designing, implementing, managing, and maintaining a virtualization infrastructure and/or who are interested in validating their skills on current Microsoft virtualization technologies.

Here the steps to request your FREE voucher :

1.      Go to : http://www.microsoftvirtualacademy.com/offers/virtualizationsquaredoffer

2.      Click on “Get Free Voucher” and log into your Microsoft Virtual Academy account (or create one).

3.      Note your voucher code and go to the Prometric website to schedule the exam.

The number of free exams is limited, so be sure to schedule your appointment to lock-in your free exam. Vouchers expire and all exams must be taken by June 30, 2014.

Good luck and have fun !

New website: Decompiler-VB.Net V3.0 Launch !

I’m very excited to have finally launched the new version of Decompiler-VB.Net website (V3.0) after a full year of development!

Yes, I finally decided to communicate after a long period of development and testing. It’s all been completely re-coded from the ground up, and definitelly yes, the new website is officially up!

Totally renovated and multi-language, it will allow me to fulfill your orders faster, to answer your questions more quickly and it will allow you to track and verify your orders and licenses more easily.

The new website is currently translated in French and English, but we plan to add many other languages. Italian, Spanish, and Chinese language will be soon available.

My goals with the new website were to make it faster, easier to navigate for users, and easier for us to manage and update.

The website will now be updated more regularly to improve your comfort by being clearer and more interactive.

Have fun and see you soon !

The truth about P-Code

I. Introduction

This article has been written to provide a better and essential information to users of decompilers since I got many complaints from customers of others Visual Basic decompilers because their application weren’t recovered by these decompilers.

The reason is, when you write a Visual Basic 6.0 application you may choose a P-Code or Native code compilation, then your application will be compiled to P-Code or Native code which are very different approaches of compilation, so the decompilation will be different too.

There is a question you may absolutely ask yourself when you need a decompiler for a specific application: Is my application compiled into native or P-Code mode ?

The main problem is that a lot of users got a P-Code decompiler in order to decompile their application, but released with Native Code…

In fact, P-Code decompiler are today almost useless because 90% of Visual Basic 6 application are released with Native Code mode. This article will explain first the difference between P-Code and Native code, and then explain why the rate of Native code application is so important compared to P-Code applications. I. P-Code Versus Native Code

When you write a line of code in the IDE, Visual Basic breaks it down into expressions and encodes the expressions into a preliminary format called op-codes. In other words, each line is partially precompiled as it is written. Some lines contain shared information that cannot be precompiled independently (mainly Dim statements and procedure definitions). This is why you have to restart if you change certain lines in break mode. The opcodes are compiled into p-code instructions when you compile (in the background if you have the Compile On Demand and Background Compile options set).

At run time, the p-code interpreter works through the program, decoding and executing p-code instructions. These p-code instructions are smaller than equivalent native code instructions, thus dramatically reducing the size of the executable program. But the system must load the p-code interpreter into memory in addition to the code, and it must decode each instruction.

It’s a different story with native code. You start with the same opcodes, but instead of translating to p-code instructions, the compiler translates to native instructions. Because you’re not going to be expecting an instant response while stepping through native code instructions in the IDE, the compiler can look at code from a greater distance; it can analyze blocks of code and find ways to eliminate inefficiency and duplication. The compiler philosophy is that, since you compile only once, you can take as long as you want to analyze as much code as necessary to generate the best results possible.

These two approaches create a disjunction. How can you guarantee that such different ways of analyzing code will generate the same results? Well, you can’t. In fact, if you look at the Advanced Optimizations dialog box (available from the Compile tab of the Project Properties dialog box) you’ll see a warning: “Enabling the following optimizations might prevent correct execution of your program.” This might sound like an admission of failure, but welcome to the real world of compilers. Users of other compiled languages understand that optimization is a bonus. If it works, great. If not, turn it off.

On the other hand, very few developers are going to be used to the idea of working in an interpreter during development but releasing compiled code. Most compilers have a debug mode for fast compiles and a release mode for fast code. Visual Basic doesn’t worry about fast compiles because it has a no-compile mode that is faster than the fastest compiler. You get the best of both worlds, but it’s going to take a little while for people to really trust the compiler to generate code that they can’t easily see and debug.

Source : http://vb.mvps.org/hardcore/html/p-codeversusnativecode.htm

II. Proportion of P-Code application in the world

The amount of P-Code developed application is very small compared to Native Code developed application (90% of Visual Basic 6 applications are compiled with Native Code setting -default setting in VB6-), that is one of the reason why I decided to develop VBReFormer more for Native Code than for P-Code.

The massive number of Visual Basic Native application compared to P-Code applications is probably more important due to the fact the default value in the compiler is set up to « Native Code », and of course because native application are almost fast than C++ applications contrary to P-Code applications.

Before choosing a decompiler you must know if it was released for Native application, or for P-Code applications, and if your application was released in P-Code or Native mode.

Note that P-Code is more easy to decompile than Native Code because of it’s high level property.

C#: How to add some SortField to a CrystalReportViewer by using reflection

I’m currently working on a client’s project on migrating an important management application initially developed in VB6 to C# by using decompilation since the client lost his source code. This is my first .Net related post.

The application uses many external components, including the powerful Crystal Report component.

While I was working on this new version I faced a problem with the .Net implementation of Crystal Report.

Actually, with Visual Basic 6.0 it was an easy task to add one or many sort fields to a report document in order to sort the result by field (for example by “Lastname”, “Firstname”, “Id”, or other).

It’s not the case with .Net implementation of Crystal Report Document, on which you cannot dynamically add sort field to your report. You must add the sort field when you’re editing your report template. It’s not really convenient when you don’t know how many fields must be sorted when creating the document.

The reason of this missing is not really clear since it’s an existing feature on Visual Basic 6.0. We will learn here how to add many SortField to the ReportDocument of a CrystalReportViewer, using reflection.

Imagine you have to sort the request’s result by “Firstname”, “Lastname”, and “Id” fields, using the Crystal report document with the variable “Filename” as the report document path, and the variable “srcDataSet” dataset as the data source:


Here we can modify the sort field (only if existing in the document):


But impossible to add directly a new field to that SortFields collection because no method allows performing action:


Actually, it’s possible to add a new sort field using the mother inherited class of each used component.

First we get the “SortFields” mother’s class of type (CrystalDecisions.ReportAppServer.DataDefModel.SortsClass ) by using the RasSorts private accessor of the SortFields object:


It return an object of type CrystalDecisions.ReportAppServer.DataDefModel.SortsClass.

Now we can access to the private “Add” method of the mother’s class:


The description of that method show that it accept one parameter of type CrystalDecisions.ReportAppServer.DataDefModel.ISCRSort.


ISCRSort is an interface, so we have to create a new instance of a class that implement the ISCRSort interface. That class is called “SortClass” and come from the “CrystalDecisions.ReportAppServer.DataDefModel” assembly.


Our “rasSort” object now instantiate the SortClass class, implementing ISCRSort.
Once the SortClass object is created, we must complete it with valid field, else it will return an error on execution.

The SortClass class uses the “RasField” accessor to define the field which will be sorted.


But this method only accepts an object implementing the ISCRField interface:
Void set_SortField(CrystalDecisions.ReportAppServer.DataDefModel.ISCRField);

So we have to extract the object of our field object (called fieldDef) that implement the ISCRField interface, it can be done with the “RasField” accessor of our DatabaseFieldDefinition object called “fieldDef”:


And now, the final touch, we add it to the collection:


Your new sort field has been adding to the SortFields collection, and you can now modify it:


That’s all.

VBReFormer: CrackMe Sample #1

Now that VBReFormer is a well advanced decompiler for Visual Basic application, I was searching for some unsolved crackmes in order to made sample of decompiling for learning purpose.

The website Crackmes.de contains an impressive number of crackmes applications, a perfect source of samples.

For the first sample of CrackMe solving with VBReFormer Professional I decided to take “Step 2” from yudi (more informations).

I will show you, step by step, how it’s simple to solve the yudi’s Step 2 using VBReFormer Professional.

  • Running the application:

yudi's Step 2 (CrackMe) / Screenshot 1

We can see that a serial is generated using the name of the user.

How the serial is generated? See the following step.

  • Now we just open the “Step 2.exe” file with VBReFormer Professional and getting the following result:

VBReFormer VB decompiler screenshot 1

  • We will now take a look to the first method loaded on Visual Basic application.

VBReFormer VB decompiler screenshot 2

We can see on this capture that the “Label4” visibility is set to False (not visible) at the beginning of the application.

Take a look to that control in the resource editor of VBReFormer and you will agree that it’s the control that show the message “Registered user!”

VBReFormer VB decompiler screenshot 3

We now need to know where the “Label4” control visibility is set to true, and what does the “Timer1” control.

  • The analysis of the Timer1 control is interesting but not very useful for the following of this tutorial.

VBReFormer VB decompiler screenshot 4

We can see here that the “Timer1_Timer” function is called every second by “Timer1” control in order to check that no debuggers, and if one is running, to close it.

We can note that it also close any MessageBox windows.

  • Now we are looking for the code under the “Try” button which check if the key match with the name.

That “Try” button is the “Command1” button in VBReFormer:

VBReFormer VB decompiler screenshot 5

Then just look to the Command1_Click() function in order to see the algorithm of key checking:


VBReFormer VB decompiler screenshot 6

The algorithm seems a little complicated for newbie, but complete and without any syntax and source code error from VBReFormer.

That’s a great thing for us; we will be able to test the application into the Visual Basic IDE later (to make a key generator for example).

By analyzing the code we can see the following:


This part of code is showing us that the key is generated from the Name, but also with the Date and the Time !

That’s meaning it’s almost impossible to generate a key that does not expire the following second.

  • In order to made the Key Generator, save the project with VBReFormer, and open it with Visual Basic 6.

When it’s opened into the Visual Basic IDE, remove the debugger watching functions and just keep the following:

o Command1_Click

o Command2_Click

Now remove the following conditions block from Command1_Click function:


These block are showing an alert when the “Name” field and when the “Key” field are empty, but it’s not usefull for a keygen.

At the end of the Command1_Click function we can see the serial check condition:


That code is checking that the serial (stored in var_pv19 variable) generated from the name with the algorithm is the same than the one entered in the “Serial” field (Text2.Text).

To show the generated serial, we just need to replace that condition block by the following line of code:

VBReFormer VB decompiler screenshot 7

You must also remove the following line of code which remove the content of the both fields:


After all change and simplifications, we have the following keygen code:


  • We now have to test our keygen:

yudi's Step 2 (CrackMe) / Screenshot 2

  • The first window is the windows of our KeyGen created from the original crackme, and the second window is the one of the original Crackme, with the key from the KeyGen.

The result is that our keygen work perfectly!

Just note that the use of date and time make your key valid for only 1 minute after having generated it.

Is it possible to bypass that limitation?

Yes it is ! In fact, to get the “Registered user!” message you even don’t need a key generator. By reading the code you can see that the operator used to perform a comparison between the both string key is the “Like” operator.

The “like” operator allows to comparate a string and a pattern…

Then you just can set “*” into the serial field and you will have a key which will be valid at anytime, with any name:

yudi's Step 2 (CrackMe) / Screenshot 3


Source code of the key generator can be downloaded here:


Enjoy it !

VBReFormer: How to alter a Visual Basic 6.0 application

One of the most exiting feature of VBReFormer is design edition mode for binaries Visual Basic applications.

I have done this webcast to show that we can easily edit and alter an executable written with Visual Basic 6 with help of my half-decompiler VBReFormer 2007 Professional Edition.

For more information about VBReFormer: http://www.decompiler-vb.net/.



New release: VBReFormer 5.4 Professional

I’m proud to announce the release and availability of VBReFormer Professional 5.4 (for licensed users).

The updated version of VBReFormer can be downloaded from your client account!

What’s new in VBReFormer Professional 5.4 ?

1. The analysis engine for disassembling and decompiling has been modified to recover language structure information (in order to decompile If/End If/Do/Loop/While blocks).

Then VBReFormer is now able to decompile simple conditions block like If/End If and Do/Loop/While conditions block.

2. The event name from controls is now back and shown on the code.

3. Conditions with Variant type and floating points type (Single and Double) is now supported because we included lot of news Visual Basic Virtual Machine functions:


4. An important bugfix has been applied. The problem was that VBReFormer sometime crashed on loading application on Windows XP, and was not showing every code from Visual Basic objects (vb6.old library was not properly setup).

5. New preference setting: You can now choose if you want to show only assembly code, only Visual Basic code, or the both.