vb.net实现木马注册机原理：动态配置exe
已经配置过的运行界面，背景是用notepad.exe打开文件可以看到文件最后的配置字符串：
主要源代码：Private Sub b_OK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles b_OK.Click
'检查配置
If Len(Me.tb_myConfig.Text) = 0 Then
Me.l_res.Text = "请输入你要设置的字符！"
Return
End If
'设置文件保存位置
Dim strUrl As String
If ofd.ShowDialog = DialogResult.OK Then
strUrl = ofd.FileName
Else
Return
End If
'复制本身到指定文件
IO.File.Copy(Application.ExecutablePath, strUrl, True)
Dim ms As IO.FileStream
Dim bw As IO.BinaryWriter
Try
' '打开文件
ms = New IO.FileStream(strUrl, IO.FileAccess.ReadWrite)
bw = New IO.BinaryWriter(ms)
'读取中文件配置的位置，以确定该文件是否被配置过
Dim ip As Integer = SeekPostion(Application.ExecutablePath)
If ip = 0 Then
'如果没有配置过，就定位到文件结尾
bw.Seek(0, IO.SeekOrigin.End)
Else
'已经配置过的话，就定位到配置位置
bw.Seek(ip, IO.SeekOrigin.Begin)
End If
'连续写2个 vbcrlf，这个就是是否被配置的标志
bw.Write(vbCrLf)
bw.Write(vbCrLf)
'这里写配置进去！
bw.Write(System.Text.Encoding.Default.GetBytes(Me.tb_myConfig.Text))
bw.Flush()
Catch ex As Exception
Me.l_res.Text = "错误：" & ex.Message
Return
Finally
'关闭文件
bw.Close()
ms.Close()
End Try
Try
'启动新程序
System.Diagnostics.Process.Start(strUrl)
'结束当前京城
Me.Dispose()
Catch ex As Exception
End Try
End Sub
Private Sub FrmMain_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'显示是否配置 以及配置结果
Me.tb_myConfig.Text = reanConfig(Application.ExecutablePath)
If SeekPostion(Application.ExecutablePath) = 0 Then
Me.l_res.Text = "该程序没有被配置过！"
Else
Me.l_res.Text = "该程序已经被配置过了！"
End If
End Sub
Function SeekPostion(ByVal strPath As String) As Integer
Dim ip As Integer = 0 '位置
Dim ms As IO.FileStream
Dim br As IO.BinaryReader
Try
ms = New IO.FileStream(strPath, IO.FileMode.Open, IO.FileAccess.Read)
br = New IO.BinaryReader(ms)
'读取文件
Dim b() As Byte = br.ReadBytes(ms.Length)
Dim ic As Integer
For i As Integer = 0 To b.Length - 5
ic = i
'这里检查标志，就是上面连续写2个 vbcrlf vbcrlf
If b(ic) = 13 And b(ic + 1) = 10 And b(ic + 3) = 13 And b(ic + 4) = 10 Then
ip = ic
Exit For
End If
Next
Catch ex As Exception
Console.Write(ex.Message)
Finally
If Not ms Is Nothing Then
ms.Close()
End If
If Not br Is Nothing Then
br.Close()
End If
End Try
Return ip
End Function
Private Function reanConfig(ByVal strPath As String) As String
Dim Ip As Integer = SeekPostion(strPath)
If Ip = 0 Then
Return Nothing
End If
Dim ms As IO.FileStream
Dim br As IO.BinaryReader
Try
ms = New IO.FileStream(Application.ExecutablePath, IO.FileMode.Open, IO.FileAccess.Read)
br = New IO.BinaryReader(ms)
br.ReadBytes(Ip + 5) '舍弃前面的数据
'读取最后的数据！
Return System.Text.Encoding.Default.GetString(br.ReadBytes(ms.Length - Ip - 5))
Catch ex As Exception
Console.Write(ex.Message)
Return Nothing
Finally
If Not ms Is Nothing Then
ms.Close()
End If
If Not br Is Nothing Then
br.Close()
End If
End Try
End Function
