In parallel with its release of 17 bulletins on Patch Tuesday this month, Microsoft also unveiled two new tools that are meant to help make a couple of common exploitation scenarios more difficult for attackers.
The company released a tool called Office File Validation for some older versions of Office, including Office 2003 and 2007. The feature is specifically designed to give users information about whether there's a potentially malicious component in an Office file that the user is trying to open. When the user attempts to open a file, the Office File Validation tool will inspect it and look for any signs of malicious behavior. If there's a problem, the user will get a warning dialog box giving him the opportunity to cancel the operation.
Attackers in the past few months have taken to embedding malicious Flash files inside Word and Excel documents as part of spear phishing campaigns. This was the primary attack vector used to compromise RSA last month.
The second enhancement Microsoft pushed out on Tuesday is an update to winload.exe, the component that loads Windows. The update is designed to help prevent some techniques that rootkits use to evade detection and remain persistent on infected machines.
"For a rootkit to be successful it must stay hidden and persistent on a system. One way we have seen rootkits hide themselves on 64-bit systems is bypassing driver signing checks done by winload.exe. While the update itself won't remove a rootkit, it will expose an installed rootkit and give your anti-malware software the ability to detect and remove the rootkit," Microsoft's Dustin Childs said.
Advisory 2501584 - Release of Microsoft Office File Validation for Microsoft Office
Consult TechNet article, Office File Validation for Office 2003 and Office 2007, for information on deployment, installation, and configuration of the Office File Validation feature for Microsoft Office 2003 and Microsoft Office 2007.Advisory 2506014 - Update for the Windows Operating System Loader
SRD Blog: The second advisory, KB 2506014, hardens Windows against kernel-mode rootkits. This specifically breaks the hiding mechanism used by the current Alureon/TDL4 rootkit family [against 64-bit operating systems]. It is an optional update available on WU and WSUS.