need help with a key-logging app

Ben

Hi, I'm a newbie to C# (so please excuse any improper terminology), and I'm trying to write a simple program that starts with windows, runs invisibly in the background, and records all of the keystrokes made on the keyboard to a text file. The program also needs a place to input preferences. My questions are: 1. Do I need to create an executable or a windows service. 2. (most importantly) How do I pass information from the keyboard through my program and into a text file (or a database). Currently, I'm trying a windows executable that uses a Notify Icon in combination with [this.hide()] to make the windows form invisible. I would really appreciate some help for a beginner, and/or any other resources to help out. Thanks all for your time and interest

8 Replies

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Ben23y ago
I found this VB code online which says something about being a key logger (I really wouldn't know, can't understand the code): Dim result As Integer Private Declare Function GetAsyncKeyState Lib "user32" (ByVal vKey As Long) As Integer Private Sub Timer1_Timer() For i = 1 To 255 result = 0 result = GetAsyncKeyState(i) If result = -32767 Then Text1.Text = Text1.Text + Chr(i) End if Next i End Sub Would this code work if it were translated to C#? It also appears that I might be able to somehow use the User32.dll to log keystrokes. Is this true? If so how can I learn more about the User32.dll? Thanks much.
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Ben23y ago
Thank you very much "jgandara"! This is a great start, however, I am a little confused by the example. Maybe you or someone else can help me. I tried the example, and set the opacity of the form to 0. The program would log keys just fine when I used alt+tab to switch to the program (i.e whenever the invisible form was active I could press keys, and it would log them). But, if I do something like creating a new folder on my desktop and renaming it, the program fails to record the keystrokes. Am I missing something in the example? Or is there something else I should be trying? Thanks again for your help!
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jrgc623y ago
Check this: http://www.c-sharpcorner.com/Code/2002/July/LeyLoggerApp.asp I downloaded the code and created a windows app. It's a little incomplete, so you have to map everykeystroke to the correct keyboard key. You can create a class that manages all the code and call it from a windows app or service. Just design it as a class and you are all set.
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chrishornberger23y ago
write it in VB using API calls then COM-Interop it to get it started?
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Ben23y ago
Microsoft says that the .net framework doesn't support global hooks. What now?
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Ben23y ago
chornberger, Thanks, I'll check it out. I appreciate your time :)
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chrishornberger23y ago
Either will work... service or executable. To do what you want will require techniques such as subclassing the WinProc and using Hooks. MSDN has a few examples of how to do system keyboard hooks and I'm sure would be a good starting spot for you. I think they have a complete sample app called "WinHooks" or "SysHooks"... something like that.
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Ben23y ago
Doesn't anybody know how to do this?
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