The Federal Communications Commission released a warning on Monday to alert consumers that there is a new fraud that has been going around over the past few months that happens in a matter of seconds. If you receive a phone call that begins with no introduction and just a simple, innocent question – hang up!

Scam artists are using your cell phone in order to get authorization in an out-of-context format. Basically, when you answer the phone they will ask you a question that they expect you to answer “yes” to. The most commonly used question is “Can you hear me?”. Most people will simply respond in affirmation, and this is then used by the scam artist as a voice signature to authorize charges using credit cards in that person’s name. The answer to their question gets recorded and saved, which can then be used by the scammer whenever they wish. It’s really that easy.

FCC says that you should hang up on these types of callers if you have no idea who they are. If you have already answered a call like this, look at your bank statements and credit card accounts to ensure that you have not been charged for things that shouldn’t be on your account.

This scam is known as “cramming” and has been around for quite a long time, but it has only recently begun to get more and more frequent. FCC Chairman Ajit Pai reported that American consumers had taken about 29 billion bot calls during 2016 – this equates to 230 of these calls per household.

The FCC urges anyone that gets one of these calls to report it immediately.