In an advisory on January 14, 2010, Microsoft said that attackers targeting Google and other U.S. companies used software that exploits a hole in Internet Explorer. The vulnerability affects Internet Explorer versions 6, 7, and 8 on Windows 7, Vista, Windows XP, Server 2003, Server 2008 R2, as well as IE 6 Service Pack 1 on Windows 2000 Service Pack 4.[36]