(Reuters) -MGM International and Caesars Entertainment were both allegedly hacked by the same group, called Scattered Spider, Bloomberg News reported on Wednesday, citing four people familiar with the matter.
Scattered Spider, also known as UNC3944, comprises hackers based in the United States and UK and has previously targeted telecommunications and business process outsourcing companies, the Bloomberg report added.
The hackers started targeting Caesars as early as Aug. 27, according to the people. The group had also demanded a ransom from MGM, while the casino operator's systems stayed paralyzed for a third day. Scattered Spider may have worked with ALPHV on the MGM hack, the report said, citing sources.
MGM and Caesars did not immediately respond to Reuters requests for comment.
The FBI said it was investigating the MGM hack. The rating agency Moody's warned the incident could negatively impact MGM's credit rating.
(Reporting by Seher Dareen in Bengaluru; Editing by Shailesh Kuber)