Excel user's are not entirely safe. A new vulnerability was found in Microsoft's spreadsheet program, Excel. This vulnerability can be exploited by hackers to create a malicious Excel document, which, when opened, would compromise the system.
Even though, as Microsoft has stated, these exploits are likely to be used in targeted attacks, the risk is still great, due to the fact that Excel is widely used in business related activities. This vulnerability could potentially be used to steal sensitive information, such as that about various transactions and whatnot.
Given the widespread use of Excel, it is likely that a malicious document will be opened, because users usually don't question the legitimacy of file of such trusted formats.
The vulnerability exists in the Microsoft Office Excel 2003 Service Pack 2, Microsoft Office Excel Viewer 2003, Microsoft Office Excel 2002, Microsoft Office Excel 2000 and the Mac version, Microsoft Excel 2004.
Not affected: Office Service Pack 3, Microsoft Office Excel 2007, Microsoft Office Excel 2007 Service Pack 1 and Microsoft Excel 2008 (Mac version).