CDK cyber attack shuts down auto dealerships across the U.S. Here's what to know.

CDK Global, a company that provides auto dealerships across the U.S. with software for managing sales and other services, has been hacked, prompting the company to temporarily shut down most of its systems. 

That is effectively preventing about 15,000 car dealerships from making sales.

"We are actively investigating a cyber incident," a company spokesperson told CBS News. "Out of an abundance of caution and concern for our customers, we have shut down most of our systems and are working diligently to get everything up and running as quickly as possible."