Hundreds of websites have been targeted by a new virus that allows hackers to steal passwords, credit card numbers, and other personal information when users merely visit an infected site, according to this Washington Post story (free registration required). The virus exploits flaws in Microsoft’s Windows Internet Explorer and Internet Information Services Web software.

In warning the public of the attacks, the U.S. Computer Emergency Readiness Team (CERT), a division of the Department of Homeland Security, recommended that Explorer users consider other browsers unaffected by the attack, such as Netscape, Mozilla, and Opera–a pretty big statement from CERT. (Mac, Linux, and other non-Windows operating systems are apparently immune, whether they use Explorer or not.) Internet Explorer users can help protect themselves by setting the browser’s security settings to “high” and turning off the JavaScript function in their browsers, but those changes can impair some browsing functions.