According to Microsoft officials last Tuesday, hackers are now exploiting a vulnerability in Microsoft Word in order to plant malware on Windows PCs. The bug, found in Microsoft Word 2002, 2003, 2007 and 2010, was patched back on November 9th, 2010, as a part of Microsoft’s monthly security update.
Word 2008 and 2011 for the Mac have been patched as well, however, Microsoft has not yet issued a fix for the same flaw in Word 2004. The attacks, on the other hand, only affect Windows versions of the suite.
According to the Microsoft Malware Protection Center (MMPC), which is the group that investigates attack codes and also issues signature updates for the company’s antivirus software, the first exploits were found last week. When the Word patch was shipped last month, the bug was rated as a “1” on the exploitability index. What that number means is that a working attack would manifest within 30 days.
The attack uses a malicious Rich Text Format (RTF) file to generate a stack overflow in Word on Windows, according to MMPC researcher Rodel Finones. Once a successful exploit takes place, the attack codes download and run a Trojan horse on the PC. Microsoft rated this RTF vulnerability as “critical” in Word 2007 as well as 2010 last month. However it was only listed as “important” in all other affected versions.
It is thought that this bug was a hacker choice due to the fact that users running Office 2007 or 2010 could be attacked if they made the simple mistake of previewing a specially-crafted RTF document in the Outlook e-mail client.
According to Jason Miller, the Data and Security Team Manager for Shavik Technologies, “Once a malformed message hits the Outlook preview pane, remote code can be executed. You should patch this right away.” This is what he said when Microsoft released the patch.
Finones stated that the code “reliably exploits this Word vulnerability” and also urged users who have yet to install the November patch to do so immediately.
Source: Computer World