A cybersecurity attack last week at MGM Resorts International that forced the company into “shutting down certain systems”. 

David Katz, a gaming industry analyst with Jefferies Group, said in a Sunday report to investors that MGM will lose up to $8.4 million daily as it gets back up and running, according to the New York Post and other outlets. He said MGM could take a 10-20% hit on revenue and cash flow “for the days that the current conditions exist.”

The shutdown prevented credit card transactions and crashed the BetMGM sports betting mobile app and company websites. It also prevented digital access to guest rooms and halted some slot machine play.

The incident has provided plenty of bad publicity, with guests last week posting videos to social media of long lines at the check-in, broken elevators and nonfunctioning slot machines.

The company said Tuesday night that resort services, dining, entertainment, pools and spas are operating normally and welcoming thousands of guests. That includes the ticket-in/ticket-out systems for slot machines, which were disabled during the shutdown to force those cashing out to wait for an attendant to pay them.

MGM wasn’t the lone resort hit with a cybersecurity attack this month.

Data from members in the loyalty program at Caesars Entertainment was compromised when an unauthorized actor acquired a copy of the program’s database, including the driver’s license and Social Security numbers of members, the resort said in a report to the Securities and Exchange Commission.

Caesars said it “identified suspicious activity in its information technology network resulting from a social engineering attack on an outsourced IT support vendor used by the company.” The company said its customer-facing operation — both in-person and mobile gaming applications — weren’t affected.

Caesars reportedly paid a multimillion-dollar ransom to hackers. MGM hasn’t.

MGM in its Tuesday night message, which was shared on social media, thanked customers for their patience. It didn't mention when online booking would return for reserving a stay.

“Your guest experience is of paramount importance to us and we look forward to speaking with you soon,” the message on the website reads. “Thank you for your patience and understanding.”