Cyberattack Shuts Down MGM Resorts; FBI Investigating

The FBI is investigating a possible cyberattack that crippled MGM Resorts International hotels and casinos nationwide Monday. 

On Monday, MGM posted on Twitter that it shut down certain systems to protect data and has hired assistance from external experts to find the cause of the problem.

"Promptly after detecting the issue, we quickly began an investigation with assistance from leading external cybersecurity experts," the statement said. "We also noticed law enforcement and took prompt action to protect our systems and data, including shutting down certain systems. Our investigation is ongoing, and we are working diligently to determine the nature and scope of the matter."

The attack impacted everything from guests accessing hotel rooms to paid parking systems to ATMs, slot machines, the company's website and mobile app. As of Wednesday morning, the website was still down. 

The issue reportedly impacted systems across the company’s U.S. properties in Las Vegas,  Maryland, Massachusetts, Michigan, Mississippi, New Jersey, New York and Ohio.

Late Monday MGM announced it was back to being operational, although its website was still down Wednesday morning.