An unknown vulnerability in some versions of Internet Explorer has been reported by various sites. Thousands of websites are affected and the exploit code install malware on a visitor’s computer.

“An attacker who successfully exploited this vulnerability could gain the same user rights as the local user. When using Internet Explorer, code execution is remote and may not require any user intervention,” said Microsoft security representatives.

Windows XP and 2003 users are the ones who are vulnerable. No patch has been released but the company posted a workaround.

Source: The Register