This indicates an attempt to exploit one of several remote command execution vulnerabilities in Microsoft Office.
The vulnerabilities are caused by an error that occurs when the vulnerable software handles a malicious RTF file. It allows a remote attacker to execute arbitrary code via a crafted RTF file.
Microsoft Office 2000 Service Pack 3
Microsoft Office XP Service Pack 3
Microsoft Office 2003 Service Pack 2
Microsoft Office 2004 for Mac
Microsoft Word Viewer 2003
Microsoft Works Suite 2004
Microsoft Works Suite 2005
Microsoft Works Suite 2006
Microsoft Word 2007
System compromise: remote code execution.
Apply the patch available from the web site: