Use-after-free vulnerability in Microsoft Internet Explorer 6, 6 SP1, 7, and 8 on Windows 2000 SP4; Windows XP SP2 and SP3; Windows Server 2003 SP2; Windows Vista Gold, SP1, and SP2; Windows Server 2008 Gold, SP2, and R2; and Windows 7

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-0...

"Microsoft thanks the following companies for working with us and for providing details of limited, targeted attacks against customers of Internet Explorer 6:

Google Inc. and MANDIANT; Adobe; McAfee; French government CSIRT (CERTA)"

http://technet.microsoft.com/en-us/security/bulletin/MS10-00...