This indicates an attempt to exploit a vulnerability in Microsoft Excel 2000 and Office for Mac 2004 and 2008.
The vulnerability is a result of the software's failure to properly import malformed .SLK files. It allows user assisted remote attackers to execute arbitrary code via a crafted .SLK file.
Microsoft Excel 2000 SP3
Office for Mac 2004 and 2008
System compromise: remote code execution.
Please refer to the following URL for the appropriate update or the patch: