Casino and lodging operator MGM Resorts shut down a number of its computer systems, including its website, in response to a "cybersecurity issue," the company said in a social media post on Monday.
The initial shutdown impacted nearly every aspect of the casino operator's business. Reservation systems, booking systems, hotel electronic key card systems, and the casino floors were all apparently impacted by the outage.
The company's email systems were also apparently taken down in response to the cybersecurity issue, and have not yet come back online.
As of Monday evening, MGM said that its casino floors were back online, but the reservation systems that power its thousands of hotel rooms and the booking system that controls reservations for its restaurants were still down.
MGM operates thousands of hotel rooms across Las Vegas and the United States. Revenue from their hotel rooms in Las Vegas outstrips the revenue directly attributed to their casino operations, according to SEC filings. The company reported Las Vegas rooms revenue of $706.7 million for the quarter ended June 30, compared to casino revenue of $492.2 million for the same period.
"We quickly began an investigation with assistance from leading external cybersecurity experts," MGM said in a post on X, formerly known as Twitter. "We also notified law enforcement and took prompt action to protect our systems and data, including shutting down certain systems."
The company did not provide any further details about the nature of the cybersecurity issue or the extent of the damage.
The outage is the latest in a series of high-profile cyberattacks on major corporations in recent months. In July, a ransomware attack on Colonial Pipeline forced the company to shut down its operations for several days, causing gasoline shortages in the eastern United States. In June, a cyberattack on JBS USA, the world's largest meatpacker, forced the company to temporarily shut down several of its plants.
The MGM outage is a reminder of the growing threat of cyberattacks to businesses of all sizes. Companies need to be vigilant about their cybersecurity practices and take steps to protect their data from attack.
In the meantime, MGM guests who are affected by the outage are advised to contact the company directly for assistance.