Microsoft has released updates for Office 2004 and 2008, which include security fixes for “vulnerabilities that an attacker can use to overwrite the contents of your computer’s memory with malicious code.”
The Microsoft Office 2004 11.5.8 update is a mere 9.7 MB, and the Microsoft Office 2008 12.2.4 update is 221.5 MB.
If you use Office, it’s a good idea to keep up with these updates, as they not only provide security fixes, but also improve performance and stability. If you haven’t kept up with Office updates, you cannot, unfortunately, apply the latest update without applying previous updates. (Microsoft does not make any combo updates like Apple does.) So you can find previous updaters for your software on this page.