I have several files which are massive in size, but should not be. The files are 20+MB and should be only around 1 MB. When opening with 7-Zip as an archive the file which is unusually large is: 'Workbook.' Also, if you can happen to open the XLS file with excel, and manage to scroll through (past the lag) it comes up with a smile-face. This is not a smile-face that should be in the file. Has anyone heard of such an attack or does anyone know of a fix?