How to deny access to folder or file [duplicate]

Answer 1

Consider using the configuration/location nodes in your web.config. Details on MSDN

<configuration>
    <location path="MySubDirectory">
        <system.web>
            <authorization>
                <deny users="*"/> <!-- Denies all users -->
            </authorization>
        </system.web>
    </location>
</configuration>

Answer 2

There are several options explained here: http://support.microsoft.com/kb/815151

Also, if you haven't already, I strongly recommend reading up on ASP.NET Authentication here: http://msdn.microsoft.com/en-us/library/eeyk640h.aspx

Edit

Since you're using Forms authentication and want to deny anonymous users, then you can create a web.confic in the swf folder and put the following in the authorization section:

<authorization>
     <deny users="?"/>
</authorization>