Thousands of car dealers across the USA get shut down in a major cyber attack.

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. General Motors dealerships rely on CDK’s systems, as does Group 1 Automotive, an auto retailer with hundreds of dealerships across the U.S. Holman, with dealerships across eight U.S. states, is another CDK client. 

“We are actively investigating a cyber incident,” a CDK spokesperson told CBS News on Wednesday. “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.” 

Later on Wednesday afternoon, CDK said that after conducting tests and consulting with third-party experts, some of its systems were back up and running. 

“With the work done so far, our core [dealer management system] and Digital Retailing solutions have been restored. We are continuing to conduct extensive tests on all other applications, and we will provide updates as we bring those applications back online,” CDK said in a statement to CBS MoneyWatch.