There are a lot of purchases you can make with the information on the front of a credit card. But ID thieves who have the card number, name, and expiration date will still hit a speedbump if they have to enter that (usually 3-digit) security code on the back of a victim’s card. Notice that we said “speedbump” and not “dead end,” because some scammers have figured out how to get this crucial info from their victims.

According to our colleagues at Consumer Reports, the security code scam works by taking advantage of the near-constant news of data breaches that have hit retailers in recent years.

Once a scammer has the main information for the card, they can call the unwitting victim, claiming to be from the bank or credit card network. The caller will say there has been a suspicious transaction alert on that card and asks the victim whether or not they made that purchase.

Since that transaction is entirely fictional, the victim will correctly state that they did not make the purchase. The caller then says they are going to open a fraud investigation ticket, and oh — by the by — can you please confirm you are the cardholder by providing the security code on the back?

Remember, the caller already has most of your card info so they can say things like “Can you verify the code on the card ending…” and then give you the actual final digits of your account.

Scammers are also good at spoofing phone numbers, so your caller ID might say “Bank of Whatever” or the number might match the phone number on the back of your card; that doesn’t mean the person is calling from that bank or that number.

Any time you get a fraud alert call:

•Don’t give the caller any information about your account—even if he already knows some of the details.

•Hang up the phone. Call the customer service number on the back of your credit card. Talk to the fraud or security department and ask about the unauthorized charges the caller told you about.

• Report the suspicious call to the FTC at ftc.gov/complaint or 877-FTC-HELP.

•Tell your friends, family, neighbors, and others about it. By spreading the word, you can help someone you care about avoid falling for a scam.

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.