S. Korean handlers are slow to take down the publicly distributed malicious code exploiting CVE-2012-0003, a vulnerability patched in Microsoft's January 2012 patch release MS12-004. We have discussed with reporters that the code has been available since the 21st, and a site appears to have been publicly attacking very low numbers of Korean users over the past day or so. The site remains up at this time.
The exploit attacks Windows Media Player code in winmm.dll and delivers a heap spray that somewhat surprisingly works on most Windows versions up through Windows Server 2008 for x64-based Systems SP 2.
Please ensure that your system is updated.