"MGM Resorts recently identified a cybersecurity issue affecting some of the company's systems," wrote MGM in a statement released on social media. "Promptly after detecting the issue, we quickly began an investigation with assistance from leading external cybersecurity experts."
"We also notified law enforcement and took prompt action to protect our systems and data, including shutting down certain systems," the statement continued. "Our investigation is ongoing and we are working diligently to determine the nature and scope of the matter." (Related: Several federal agencies HACKED as part of global cyberattack that exploited a flaw in popular file-sharing software.)
The extent of the breach is still unclear, but it is known that all of MGM's properties on the four-mile-long Las Vegas Strip have been affected. The company has about 48,000 rooms in the company's properties on the boulevard, including in Mandalay Bay, the Bellagio, Luxor and MGM Grand.
Other affected properties include the Aria, The Cosmopolitan of Las Vegas, Delano Las Vegas, Excalibur, New York-New York, NoMad Las Vegas, Park MGM and Vdara.
MGM properties outside of Las Vegas that were also at least partially affected by the cyberattack include the Beau Rivage in Mississippi, Borgata in New Jersey, Empire City Casino in Yonkers, New York, MGM Grand Detroit in Colorado, MGM National Harbor in Maryland, MGM Northfield Park in Ohio and MGM Springfield in Massachusetts.
The cyberattack was first detected in Las Vegas Sunday night, Sept. 10, when company emails were affected and customer reservations and room keys and slot machines on casino floors also began malfunctioning.
Guests reported on social media that the incident prevented ATMs within MGM properties from dispensing cash. Slot machines also became unplayable. Hotel restaurants were also unable to process credit card payments, forcing them to only accept cash, and guests also reported they could not charge anything to their rooms with their credit cards and were unable to use their digital room keys.
"Everything down still. No ATMs. No withdrawals from cashier. Now all the slots seem to be going down," reported one individual staying at an MGM property at the time of the incident.
A day after the incident began MGM Resorts casino gaming floors were brought back into operation, but guests were still unable to enter their rooms using their digital room keys. They were forced to request physical keys to their rooms at the front desk of hotels.
Guests who still wanted to book rooms at MGM properties despite the incident were told that they may make bookings not online but over the phone by calling company hotlines.
A source with knowledge of the incident informed TechCrunch that all of MGM's properties in the United States were affected by the cyberattack. The websites of several of MGM's regional resorts, including MGM Springfield, National Harbor and Empire City, were forced to shut down.
Many MGM computer systems are likely to remain offline for several more days until the extent of the cyberattack has been made clear to the company and to local, state and federal authorities. The Federal Bureau of Investigation has already been made aware of the incident and has been in contact with MGM Resorts and is assisting in the investigation.
The last time MGM experienced a cybersecurity issue was in 2019, when the personal information of 142 million past and current guests was stolen by hackers and shared on Telegram as well as posted for sale to a dark web marketplace. The affected data included full names, postal addresses, email addresses, phone numbers, dates of birth and, in some cases, driver's license and passport numbers.
Learn more about the threat of cyberattacks at CyberWar.news.
Watch this video discussing the recent global cyberattack that affected several U.S. government agencies.