The Better Business Bureau of western Michigan says hackers are posing as customer service personnel from big name companies, like Wal-Mart, UPS, and Fed-Ex. One such message will tell you a package you ordered could not be delivered and to print a copy of an invoice attached to the e-mail. The attachment is actually a virus that will infect your computer. If you get one of these e-mails do not open them, instead call the company directly to confirm details.