A new virus is circulating in the form of a CNN Daily Top 10 newsletter (my brother was an unfortunate victim).  A description was posted at http://blog.mxlab.be/2008/08/04/cnn-daily-top-10-leads-users-to-site-hosting-malware/.  Postings on that site say that the AntiVir free antivirus and ComboFix will remove it.