The e-mail uses the the phrase "F.B.I. vs. Facebook" in its subject line and contains a link to view an article about the FBI and Facebook, a popular social networking website. Clicking on the link downloads malicious software onto the victim's computer.
"The spammers spreading this virus are preying on Internet users and making their computers an unwitting part of criminal botnet activity," said the FBI in a press release. "We urge citizens to help prevent the spread of botnets by becoming web-savvy."
The FBI is warning users not to respond to spam e-mail and not to open attachments or links provided within such e-mail, and advising them to validate the legitimacy of the e-mail by typing the organization's Web site address directly into a browser window, rather than clicking on a provided link.