Attackers have created a fake Facebook email account cancellation request which prompts the user to click a link to confirm or cancel the request. If the user follows the link, they're asked to install a Java applet. The link then tells them that need to install a plugin to update their Flash player, but will instead receive trojan malware.
Attackers are counting on the fact that Facebook users won't want to lose their contacts with family and friends and will be duped into clicking the link.
Full story with screenshots of the email here: Facebook account cancellation malware poses as Adobe Flash update