hooking another program's calls to winapi functions in vb.net - vb.net

Question

I have been trying to build a game bot in vb.net. One of the main problems is getting access to the text the game prints on the screen so I have been trying to hook the games calls to the windows api drawtext and textout functions. I have been hunting for examples of how to set up a hook in vb.net for a long time without any luck. I have found it impossible to translate examples in old school vb, C++, and C#. For convenience's sake I would like to use the freely available deviare and/or easyhook libraries. Can anyone help?

Answer 1

I found working vb.net code based on the deviare hooking dlls buried in the deviare forums.
please remember to add all 6 deviare references found under the com tab of the add references page of visual studio after installing deviare.
Public Class Form1
'To print to a textbox in the gui you will have to call textbox.invoke
Private _mgr As Deviare.SpyMgr
Private WithEvents _hook As Deviare.Hook
Private _proc As DeviareTools.IProcess
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
_mgr = New Deviare.SpyMgr()
_hook = _mgr.CreateHook("user32.dll!ShowWindow")
_hook.Attach(_mgr.Processes)
_hook.AddProcessFilter(0, "notepad", 1)
_hook.Hook()
Private Sub OnFunctionCalled(ByVal proc As DeviareTools.IProcess, ByVal callInfo As DeviareParams.ICallInfo, ByVal rCall As Deviare.IRemoteCall) Handles _hook.OnFunctionCalled
Debug.Print("Caught function call in " & proc.Name) 'view in imediate window
End Sub
end class

Answer 2

I am in the process of converting the Easyhook c# code into vb.net. At the moment I am getting the error code 5 message and the hooked application is being closed by windows eg to help protect your computer etc. If anyone could help with this then I would be grateful. What I have so far is...
Imports EasyHook
Imports System
Imports System.Diagnostics
Imports System.Runtime.Remoting
Imports System.Windows.Forms
Imports System.Security
Imports System.Security.Principal
Namespace FileMon
Friend Class Program
' Methods
Public Shared Sub Main(ByVal args As String())
Dim result As Integer = 0
If ((args.Length <> 1) OrElse Not Integer.TryParse(args(0), result)) Then
Console.WriteLine()
Console.WriteLine("Usage: FileMon %PID%")
Console.WriteLine()
Else
Try
Try
Console.WriteLine("Registering Application")
Console.WriteLine()
Config.Register("A FileMon like demo application.", "FileMon.exe", "FileMonInject.dll")
Catch exception1 As ApplicationException
Console.WriteLine("This is an administrative task! " & exception1.ToString)
Console.WriteLine()
Process.GetCurrentProcess.Kill()
End Try
Console.WriteLine("Creating IPC Server")
Console.WriteLine()
RemoteHooking.IpcCreateServer(Of FileMonInterface)(Program.ChannelName, WellKnownObjectMode.SingleCall)
RemoteHooking.Inject(result, "FileMonInject.dll", "FileMonInject.dll", New Object() {Program.ChannelName})
Console.WriteLine("Injected")
Console.WriteLine()
Console.ReadLine()
Catch exception As Exception
Console.WriteLine("There was an error while connecting to target:" & exception.ToString)
End Try
End If
End Sub
' Fields
Private Shared ChannelName As String
End Class
End Namespace
and
Imports System
Namespace FileMon
Public Class FileMonInterface
Inherits MarshalByRefObject
' Methods
Public Sub IsInstalled(ByVal InClientPID As Integer)
Console.WriteLine("FileMon has been installed in target " & InClientPID)
End Sub
Public Sub OnCreateFile(ByVal InClientPID As Integer, ByVal InFileNames As String())
Dim i As Integer
For i = 0 To InFileNames.Length - 1
Console.WriteLine(InFileNames(i))
Next i
End Sub
Public Sub Ping()
End Sub
Public Sub ReportException(ByVal InInfo As Exception)
Console.WriteLine(("The target process has reported an error:" & InInfo.ToString))
End Sub
End Class
End Namespace

Answer 3

easyhook libraries
Try to use the EasyHook library