I don’t think there is such a type of .ashx.vb file.
Try changing the top line to:
<%@ WebHandler Language="VB" Class="Upload" %>
and then just put the code after the code in the .ashx file
<%@ WebHandler Language="VB" Class="Upload" %>
Imports System
Imports System.Web
Public Class Upload : Implements IHttpHandler
'Code here....
End Class
Alternatively, did you try to create your code?
See this similar question for more help:
Http IIS7 and ASP.NET Custom Handlers