Zip email attachments with xls files and dangerous macros not being detected?

Hi,

Although Office can detect if a macro is suspicious, it seems that on some recent spam emails there are zip attachments which as far as I can see contain excel files. I detached one of these (not opened!) and scanned it with BitDefender and it showed as clean.

Does Total Security detect macros embedded in xls files or is that down to Office programs?

I did submit the email using the BitDefender toolbar.

Thanks.