If so, check for the presence of the file
include/feeds/index.php and delete it if it exists. It's a file upload script that should not have been included in the distribution.
I was working with a friend that uses that cart when I discovered this file. TWT support verified that it should not be there. This file was included with their software distribution, and I've verified it by finding another SunShop site which we have no affiliation with that also has this script present.
At this point, I don't have any other details than what I've posted. As of an hour or so ago, the downloadable distribution files available from TWT still contained this file, and I haven't seen any other announcements about it.
You heard it here first!