Web Security: File extension blocking inside archives
the need to block specific file types will have multiple customers and with the Extension-filter it works just under the circumstances that files are not inside an archive.
There is the need to block these files also in f.e. "ZIP" archives.
Using Sophos True File Type detection, Sophos UTM 9.3 can now inspect inside ZIP files and determine what file types exist inside the ZIP. If these files are blocked by policy, the whole ZIP will be blocked.
For more information about UTM 9.3, see the following blog post: http://blogs.sophos.com/2014/11/10/sophos-utm-advantage-9-3-is-coming-soon-find-out-whats-new-2/
This option is not working for the Web Proxy, it only works for Email Protection.
Daryn C. commented