X97M/Extras is a macro virus written in Visual Basic for Applications and is the first polymorphic macro virus to infect XLS files within Microsoft Excel v.8.0.
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.
Extras changes its appearance so it looks different in every infected file.
The virus also creates an infected Excel spreadsheet within the Excel startup directory.
Extras activates on and after January 1st, 1999. At this time, the virus will try to remove all menus from Excel interface.
X97M/Extras has nothing to do with the WM/Extra Word macro virus.
Technical Details: MHH//DF