A new computer virus dubbed "Killer Resume" is spreading through email systems using the Microsoft Outlook program, the FBI said.

Anti-virus companies reported late Friday that several corporate email systems had already been infected, and some shut down, the FBI's National Infrastructure Protection Center said. The virus, similar in makeup to the notorious Melissa virus, is carried in a file attached to an email with the subject "Resume - Janet Simons." The attachment is a Microsoft Word file called "EXPLORER.DOC" or "RESUME.DOC," according to an alert posted on the Web site of computer security company Network Associates. Network Associates as of Saturday morning classified the virus as "medium on watch," according to the company's Web site. If a computer user opens the attachment, the virus will spread itself by sending an email to everyone in the user's email address book, the company said. When the user closes the Word document, the virus will then delete important files on the user's computer. The FBI advised computer users not to open any email with this subject line, to deactivate the executive summary feature in Microsoft Outlook, and then delete the email without opening it.