A new virus — known variously as Tanatos and W32/Bugbear — is being circulated by e-mail and appears to be targeting computers running Windows and Internet Explorer. The e-mails come with a variety of titles, like “bad news,” “Membership Confirmation,” “Market Update Report,” and “Your Gift,” in an apparent attempt to avoid virus detection. Make sure you update your anti-virus definitions, download the latest Internet Explorer patches (if you haven’t already), and be careful about opening attachments from senders you don’t recognize.