Microsoft Office Excel 2000 SP3 2002 SP3 2003 SP3 and 2007 SP1; Excel Viewer 2003 Gold and SP3; Excel Viewer; Compatibility Pack for Word Excel and PowerPoint 2007 File Formats SP1; and Excel in Microsoft Office 2004 and 2008 for Mac allow remote attackers to execute arbitrary code via a crafted Excel document that triggers an access attempt on an invalid object as exploited in the wild in February 2009 by Trojan.Mdropper.AC.