You receive a phone call from someone who identifies himself as a Visa or MasterCard representative. He asks if you authorized a particular purchase (often electronics). You did not. The representative explains that someone has stolen your credit card number and is running up your bill. "Don't worry," the rep says, "I can help you cancel the card and have the fraudulent charges removed from your account."
How It Works
This caller does not really work for a credit card company, and your card number has not really been stolen, yet. The caller is a con artist who will ask you to "confirm" your credit card number and perhaps the three-digit code on the back of the card while pretending to help you stop a fictitious thief.
Never divulge your credit card number or the code on the back of your credit card to anyone who phones you, even if he/she claims that you must act fast to protect your account. Hang up, phone your credit card company's toll-free number and ask a real credit card company representative to check for the fraudulent charge that the caller mentioned, as well as for any other suspicious activity. If there is any sign of trouble, cancel the card. Also, check your accounts regularly online for any fraudulent charges.