A couple of days ago Microsoft released a security update, which includes repairs to Excel, because that could allow third parties to control the PC of its users.

Adobe Systems also added a patch for Flash Player in order to fix a vulnerability in its latest version, same as intruders are exploiting to achieve greater access to PCs

The Adobe Security engineers investigated the vulnerability of the system to find and integrate the solution into the latest software upgrade of the company, said Brad Arkin, senior director of security products at Adobe.

Meanwhile, Microsoft released 10 updates to address the 34 identified bugs in Office, Windows, Internet Explorer and other products.

Three of the patches were of high priority and should be deployed immediately to protect users from potential attacks.

Fourteen of the Excel vulnerabilities were identified, eight of the Windows operating system and Internet Explorer. A total of 34 faults that tied a major safety problem emerged in 2009.

Flaws in the application of spreadsheets allowed the intruders to create corrupt files that infect computers, allowing third parties could gain remote control of the machine, according to Joris Evers, a spokesman for security software maker McAfee.

So now you know. If the system asks if you want to download an update, the recommendation is to say yes.