Attack code targeting the Internet Explorer vulnerability used to hit Google and other companies has hit the Web.
According to McAfee, researchers have seen references to the code-which exploits an unpatched vulnerability in Microsoft Internet Explorer-on mailing lists and have confirmed that the code was published on at least one Website. The code was used to attack Google and others in a spate of cyber-attacks believed to have originated in China.
The attacks have sparked controversy and prompted Google to threaten to pull out of China altogether. Officials at the U.S. State Department have stated they plan to get answers from China as to what happened in the coming days.
"The public release of the exploit code increases the possibility of widespread attacks using the Internet Explorer vulnerability," McAfee CTO George Kurtz posted on the McAfee Security Insights blog. "The now public computer code may help cyber-criminals craft attacks that use the vulnerability to compromise Windows systems. Popular penetration-testing tools are already being updated to include this exploit. This attack is especially deadly on older systems that are running [Windows] XP and Internet Explorer 6."
Microsoft stated in an advisory that though the attacks have been focused on IE 6, versions 7 and 8 are vulnerable as well. The vulnerability, the company said, is due to an invalid pointer reference in IE.
"It is possible under certain conditions for the invalid pointer to be accessed after an object is deleted," the Microsoft advisory said. "In a specially crafted attack, in attempting to access a freed object, Internet Explorer can be caused to allow remote code execution."
To mitigate the problem, users can enable DEP (data execution protection) or disable active scripting in the Internet and Local Intranet security zones. Users can also configure Internet Explorer to prompt before running active scripting.