The linked article is down, here's an archive https://web.archive.org/web/20230911174437/https://www.casino.org/news/mgm-resorts-suffers-cybersecurity-attack-sy

The linked article is down, here's an archive https://web.archive.org/web/20230911174437/https://www.casino.org/news/mgm-resorts-suffers-cybersecurity-attack-system-outage-reported/ https://web.archive.org/web/20230911174437/https://www.casin... Though the article itself says details are scant, so it's just going to be speculation. I'd love to know what happened though.