I recently downloaded a .ZIP file using Safari. Safari informed me that it had detected an executable file inside the archive (which was not supposed to contain any executables), but no obvious executables seemed to be present upon un-archiving it. I've since deleted the files/folder, but I believe it was mostly .html and .jpg files. However, there were also some Thumbs.db files probably left over from the Windows system on which it was zipped...could Safari have mistaken them for UNIX executables? How would I know what Safari warned was an executable? How would I detect a hidden virus?