A phone call to helpdesk was likely all it took to hack MGM

A cyber criminal gang proficient in impersonation and malware has been identified as the likely culprit for an attack that paralized networks at US casino operator MGM Resorts International.

The group, which security researchers call “Scattered Spider,” uses fraudulent phone calls to employees and help desks to “phish” for login credentials. It has targeted MGM and dozens of other Western companies with the aim of extracting ransom payments, according to two people familiar with the situation.

The operator of hotel casinos on the Las Vegas Strip, including the Bellagio, Aria, Cosmopolitan, and Excalibur, preemptively shut down large parts of its internal networks after discovering the breach on Sunday, one of the people said.

The effort to contain the hackers caused chaos. Slot machines stopped working, electronic transfers of winnings slowed down, and key cards for thousands of hotel rooms no longer functioned. MGM did not respond to a request for comment.

The FBI said it was investigating, and the Nevada Gaming Control Board was informed of the breach’s impact, with the state’s governor, Joe Lombardo, coordinating with local and national law enforcement, the board said in a statement.

Scattered Spider is a relatively new entrant in the ransomware industry and has hit at least 100 organizations, most of them in the US and Canada, in the two years that Mandiant has been tracking it, said Charles Carmakal, chief technology officer at the Google-owned cyber security group.