Fake emails are a common attack vector for cybercriminals. Crafted carefully, these can deal significant damage to the victim. In a recent observation, crooks target premium LogMeIn users by delivering them a fake invoice document, which is actually a malware dropping tool. The message appears to come from LogMeIns auto-mailing system, and the subject line informs that it includes an invoice for the service. It informs the potential victim that the Pro subscription for the service is d…