Attackers are actively exploiting one of the 11 Internet Explorer vulnerabilities patched by Microsoft last week.
Symantec has identified an in-the-wild exploit targeting the Timed Interactive Multimedia Extensions memory corruption flaw that was fixed as part of a cumulative patch for IE.
While the vulnerability impacts versions 6, 7 and 8 of the web browser, researchers at Symantec have only witnessed an exploit that affects users running version 8.
Attacks appear to be happening on a fairly limited and targeted basis, Joji Hamada, a senior security researcher, said in a blog post. Symantec has confirmed at least one attack in which the website of a restaurant was compromised to deliver the exploit, dubbed Trojan.Shixploit, via a hidden IFRAME.
The vulnerability involves the way that IE "accesses an object that has not been correctly initialised or has been deleted" and may allow for the execution of arbitrary code, according to Microsoft.