Officials are warning about a new scam that starts with a single ring and then disconnects before you pick up.

If you call back the number, that’s when you get scammed! The con artists behind this scheme charge your account $20 for the call and $9 a minute after that!

These phone scammers are using numbers that all come from outside of the U.S. and authorities are warning which ones you need to be especially wary of, including 268, which is Antigua; 809, which is the Dominican Republic; 876 from Jamaica; 284 of the British Virgin Islands; and 473, which is Grenada.

The scammers are believed to have stolen a list of numbers and are now calling as many people as possible.

So the next time you get a missed call from some unknown person, don’t you dare dial them back, it will cost you.