If you like your dentist, *call* them, today. http://krebsonsecurity.com/2016/04/dental-assn-mails-malware-to-members/, and the URL says it all - they mailed a card with a USB key... and some of them have malware, and Krebs says not all virus scanners can detect it....

mark "got off the phone with my dentists' office a few minutes ago