This indicates an attempt to exploit one of several of remote vulnerabilities in the spreadsheet component of Microsoft Works.
Microsoft Works fails to handle specifically crafted spreadsheet documents when importing them. An attacker can use this vulnerability to launch a Denial of Service attack against the user. It has been reported that code execution is also possible.
Microsoft Works 8.0
Denial of Service
System compromise: remote code execution.
Currently Fortinet is not aware of any vendor-supplied patches for this issue.
Do not accept, open or execute files from untrusted or unknown sources.
Use administrative accounts only for administrative purposes. Normal every day tasks should be performed using an unprivileged account.
Do not open any files that originate from an untrusted source. Malicious Microsoft Works files may be sent in email, hosted on a Webpage, or sent through other avenues such as instant messaging.