[LordCoder]

Hello,
As I see some people are confused creating a builder for stub files I decided to create a complete tutorial.
If you don't know what does builder or stub mean let me show you an example.

You have an application that shows a message. That message can be anything. The user who creates the application needs to set a custom message as he's trying to do, for example, an application saying "Hello".

There are 3 ways (I think there aren't any other). The first one is using Mono.Cecil, an open source library to edit already compiled assemblies for .NET. It will edit us whatever we want inside the application using MSIL. The problem is to know how to use it (so this method could be more advanced if you are not into reversing).
The second method is using a part from the compiled .EXE and then get it. The options should be inside the application and you can't change the code. That's useful if you're going to make similar stubs and not very customized.
The last method is using a stub code and edit it as we want. Then compile it using some classes from .NET. This might be a good method if you're planning to do an easy application without many classes or references (as you will have it on a .txt file basically).

1st way: Mono.Cecil
Download Mono.Cecil.dll (already compiled for you).

I'm not going to show the basic of Mono.Cecil as there are a lot of tutorials about Mono.Cecil (or remember Google is your friend always).

Creating a basic "MsgBox Creator" application
-Create 2 projects: Builder and Stub.
-Add Mono.Cecil to your project.

On the Stub you should use, for example, a ConsoleApplication. On MainModule1 put:

Code

Function GetMessage() as String
Return "Not Set - Error" ' Builder will do the job
End Function
Sub Main()
Dim msg as String = GetMessage
If msg = "Not Set - Error" Then ' Checks if Builder did it
MsgBox("No message was set. Closing now.")
Else
MsgBox(msg)
End If
End Sub

Now save it to "YourBuilderProject\bin\debug\stub_compiled.exe" and add this to the Builder:

Code

Sub Compile(ByVal message As String)
      Dim m As AssemblyDefinition = AssemblyDefinition.ReadAssembly(Application.StartupPath & "\stub_compiled.exe") ' Opens our stub
      For Each i In m.MainModule.Types
      If i.Name = "MainModule1" Then ' Finds the MainModule of the ConsoleApplication
      For Each Me2 In i.Methods
      If Me2.Name = "GetMessage" Then ' Finds the GetMessage function
      Me2.Body.Instructions(1).Operand = message ' I put 1 instead of 0 because compilers should put always a 'Nop' instruction before the code
      End If
      Next
      End If
      Next
      m.Write(Application.StartupPath & "\stub_edited.exe") ' Saves the assembly
    End Sub

Finally run "Builder" and call "Compile" sub with any message. It will save "stub_edited.exe" with your new message.

2nd way: Editing options from an EXE
This method doesn't require any extra library. I know my code is very old and I can use IO functions but I like it. I'm not going to make this thread more long to explain how does it work, it just works.

Creating a basic "MsgBox Creator" application

As we did with the Mono.Cecil example, create both projects "Stub" and "Builder". The stub can be a ConsoleApplication like before with this method:

Code

Sub Main()
Dim options as String()
Dim text1 as String
FileSystem.FileOpen(1, Application.ExecutablePath, OpenMode.Binary, OpenAccess.Read, OpenShare.Shared, -1) ' Opens the file and saves to a local variable 1.
Me.text1 = Strings.Space(CInt(FileSystem.LOF(1))) ' Gets the variable
FileSystem.FileGet(1, Me.text1, -1, False)
FileSystem.FileClose(1)
Try
Me.options = Strings.Split(Me.text1, "WHATEVERHEREWITHOUTSPACES", -1, CompareMethod.Binary)
Catch ex as Exception
Msgbox("Error. No message was set")
End
End Try
MsgBox(options(1))
End Sub

Compile it and do the same (copy the file to bin\debug as "stub_compiled.exe"). Then add this code:

Code

Sub Compile(message as String)
  FileSystem.FileOpen(1, "stub_compiled.exe", OpenMode.Binary, OpenAccess.Read, OpenShare.Default, -1)
      Dim str As String = Strings.Space(CInt(FileSystem.LOF(1)))
      FileSystem.FileGet(1, str, -1, False)
      FileSystem.FileClose(New Integer() { 1 })
      FileSystem.FileOpen(1, Me.SaveFileDialog1.FileName, OpenMode.Binary, OpenAccess.ReadWrite, OpenShare.Default, -1)
      FileSystem.FilePut(1, (str & "WHATEVERHEREWITHOUTSPACES" & "YOURMESSAGEHEREIFUWANT"), -1, False)
      FileSystem.FileClose(New Integer() { 1 })
End Sub

Remember that "WHATEVERHEREWITHOUTSPACES" should be the same for builder and stub and without spaces.

3rd way: Compiling a new assembly
You'll need System.Reflection namespaces so add them with Imports.

Creating a basic "MsgBox Creator" application

The trick to do this is editing the stub but as a text file. So let's say we have this:

Code

Module MainModule1
Sub Main()
MsgBox("WHATTOSAY")
End Sub
End Module

We'll have to edit the stub to:

Code

mystubsaved.Replace("WHATTOSAY", "Hey this is the new message")

And then compile it:

Code

Public Sub CompileCode(ByVal is_vb As Boolean, sourceFile As String, _
    exeFile As String)
      Dim provider
      If Not is_vb Then
      provider = New CSharpCodeProvider()
      Else
      provider = New VBCodeProvider()
      End If
      Dim cp As New CompilerParameters()
      cp.ReferencedAssemblies.Add("System.dll")
      ' NOTE: If your stub has more references you need to add them
      cp.GenerateExecutable = True
      cp.OutputAssembly = exeFile
      cp.GenerateInMemory = False
      Dim cr As CompilerResults = provider.CompileAssemblyFromFile(cp, sourceFile)
End Sub

That's all! I didn't explain everything step by step as I suppose you know about VB.NET.

Any comments are welcomed (I expect the bad ones too, please be bad with me because I can learn from those comments :D).

[Nutrition]

This is actually really helpful and informational!

[bfizzy]

I am getting this error with the first method.
anything wrong from my side?

My Code:




Error:

[SIM-1456245]

This is one heck of an impressive tutorial. Well done.

[LordCoder]

I am getting this error with the first method.
anything wrong from my side?

My Code:




Error:

The function that returns the message should return a string, not an integer.

[bfizzy]

The function that returns the message should return a string, not an integer.

ohh, what a mistake
I will try it out as I get home.

[TheBarret]

ohh, what a mistake
I will try it out as I get home.

If you don't know that, why the heck are even trying to make this.

So much fail.

[Proton!]

Good tutorial, is the second one compatible with crypters?

[LordCoder]

Good tutorial, is the second one compatible with crypters?

Yes, but only if you use it properly.

[BahNahNah]

There is also EOF (not recommended), and updating a native resource containing the settings on a compiled assembly.

[LordCoder]

There is also EOF (not recommended), and updating a native resource containing the settings on a compiled assembly.

I wrote this a year ago 🤣

[SIM-1676753]

I use native methods such as 'LockResource' and 'LoadResource'. Simple and easy.

[ShittyAdvice]

There is also EOF (not recommended), and updating a native resource containing the settings on a compiled assembly.

Any specific reasons why it's not recommended?
Also what would be the "best" way be and why?

[Reverse_Engineer]

Good tutorial , Thanks for sharing this

[Cecilia]

Your first method isn't too great, it can be improved.
GetTypes() gets all types in the module, including nested.