The vulnerability is found in the implementation of VML -Vector Markup Language- derived from XML and used in delivering vector graphics with geometrical shapes and mathematical equations, in Internet Explorer. File formats such as SWF(Flash), PDF(Adobe Acrobat), AI (Adobe Illustrator), EMF (Microsoft Enhanced Metafile) are examples of vector graphics.

Exploit.HTML.VML pushes other malware into computers by inducing a Stack Buffer Overflow, when a smartly crafted page with VML containing a long "fill" method inside a "rect" tag, is displayed in IE. In a typical scenario, Internet Explorer is seen crashing soon after the exploit is delivered.

Microsoft has confirmed that the vulnerability allows the malware author to execute arbitrary code on the attacked system while acknowledging that a successful intruder can gain local user rights on victim's computer. The corporation is working on a patch for the flaw and if the situation warrants, would go for an earlier release of it, before its monthly patching cycle scheduled on October 10.

This is a Drive-by Download Attack using a Zero-day vulnerability, making it a definite case of clear and present danger. Just by visiting shady websites, community portals or photo exchange sites where user posted content is hosted without much supervision, you could well be inviting sly malware right into your PC.

Mail Clients like Outlook Express that preview emails, using IE rendering mechanism, is also at equal risk. Potential large scale attacks via email using VML embedded HTML, can be launched to invade user computers, where all you need is to view the mail, to be ambushed.