(Bloomberg) — Cognizant Technology Solutions Corp., one of the world’s largest providers of IT services, said it became a victim of a ransomware attack that has caused disruptions to its clients.

The company, which has about 300,000 employees, said it was hit by the “Maze” ransomware group and is engaging law enforcement authorities.

The anonymous hackers behind Maze have made headlines in recent months for publicly holding its victims hostage by threatening to leak company information if the target doesn’t pay its ransom.

“Cognizant can confirm that a security incident involving our internal systems, and causing service disruptions for some of our clients, is the result of a Maze ransomware attack,” the company said in a statement. “Our internal security teams, supplemented by leading cyber defense firms, are actively taking steps to contain this incident.”

Hackers linked to Maze have denied involvement in the attack on Cognizant, according to computer security blog BleepingComputer. That does not mean, however, that Maze isn’t responsible for the attack, according to Brett Callow, a threat analyst at Emisoft.

“The group could simply be A/B testing alternative negotiating strategies to see whether permitting companies to control the release of information, at least during the early stages, results in better outcomes,” Callow said in an email. “At this point in time, groups are likely not finding it so easy to extort money from companies as many are financially distressed due to the Covid-19 pandemic.”

The alleged targets of Maze have included the city of Pensacola in Florida, cybersecurity insurance provider Chubb Ltd. and Canadian construction company Bird Construction Inc., according to various media reports. The Maze group has claimed to post files from all three companies on its website.

In January, the Federal Bureau of Investigation issued an alert warning to U.S. companies about the Maze tactic of threatening to release company information, CyberScoop reported, citing an advisory it obtained.

Cognizant shares have declined 13% this year, compared with the 11% drop in the S&P 500 Index.