According to the Better Business Bureau, you need to scan your credit card statement to see if you've been charged for exactly $9.84.  Apparently a giant network of scammers around the world has been making those small charges on a large number of people's credit cards.  The $9.84 charge will look like it's from a generic company.  If you do have a random $9.84 charge on your card, call your credit card company immediately, report it, and get a new card.