this is a little snippet that could be very useful in a crypter.
What it does is check to see if the selected file path is .NET dependent and returns true if it is or false if it isn't.

     Public Function isNET(ByVal filepath As String)

        Dim sFile As Byte() = File.ReadAllBytes(filepath)

        If sFile(&H3C) = &H80 Then

            Return True

        Else

            Return False

        End If

    End Function

Example Use:
If isNET(ofd.filename) = true then
msgbox(".NET File")
else
msgbox("No .NET")
end if


Credits to Rue for the working C# check
Credits to me for vb and putting it in function
-Enjoy