Cognizant Technology Solutions revealed on 18 April it had been hit by a "Maze" ransomware cyber attack, resulting in service disruptions for some of its clients.
The information technology services provider said it was taking steps to contain the incident, with the help of cyber defense companies, and has also engaged with law enforcement authorities.
According to cybersecurity firm McAfee, hackers who deploy Maze threaten to release information on the internet if the targeted companies fail to pay.
"We are in ongoing communication with our clients and have provided them with indicators of compromise and other technical information of a defensive nature," Cognizant added.
It did not respond to a request for further comments on the incident.
The Maze operators denied responsibility for the cyber attack, according to security website BleepingComputer. However, the report added that Maze is likely not discussing it to avoid complications at this early stage.
Insurer Chubb Ltd in March was hit by a computer security incident that may have involved unauthorized access to data held by an outside service provider. A group that deploys the Maze ransomware claimed to have locked up devices on Chubb's network during March, according to BleepingComputer.
(Reporting by Shubham Kalia in Bengaluru; Editing by Daniel Wallis and Sandra Maler)