Concert promoter Live Nation says it is investigating a cyber attack at its Ticketmaster unit, days after experts urged customers to change their passwords.
Hackers are allegedly offering to sell customer data on the dark web.
The US entertainment giant said it had discovered “unauthorised activity” on 20 May in a third-party cloud database that mostly contained Ticketmaster data.
Live Nation added that “a criminal threat actor offered what it alleged to be company user data for sale via the dark web” on 27 May.
It comes a few days after a little-known cybercrime group named ShinyHunters reportedly said it had stolen user data of more than 500 million customers of the online ticket sales platform.
The hackers are reportedly demanding around $500,000 (£400,000) in a ransom payment to prevent the data being sold.
The breach has not had and is unlikely to have a material impact on Live Nation’s business, the company stated.
Customers were urged by experts to change their passwords after the hacking claims emerged.
The Times reported names, addresses, emails, phone numbers and the partial credit card details from Ticketmaster were being offered for sale online.
ShinyHunters posted samples of the information on a hacker forum while asking $500,000 for a “one-time sale”, the publication added.
Live Nation did not mention ShinyHunters in its filing with the US Securities and Exchange Commission.
The firm said: “We are working to mitigate risk to our users and the company, and have notified and are cooperating with law enforcement.
“As appropriate, we are also notifying regulatory authorities and users with respect to unauthorised access to personal information.
“We continue to evaluate the risks and our remediation efforts are ongoing.”
Authorities in Australia and the US are reportedly talking to Ticketmaster to understand and respond to the incident.
Companies face legal action
Ticketmaster, which merged with Live Nation in 2010, is the world’s largest ticket seller across live music, sports, theatre and other events.
The breach comes at a time when the two companies face legal action over competition concerns.
The US government wants to break them up, accusing the firms of running an illegal monopoly over live events in America.
The companies are also facing a landmark consumer class action lawsuit which is seeking $5bn (£4bn) in damages on behalf of potentially millions of ticket purchasers.
“It’s time for fans and artists to stop paying the price for Live Nation’s monopoly,” US attorney general Merrick Garland said.
“It is time to restore competition and innovation in the entertainment industry. It is time to break up Live Nation-Ticketmaster.”
Ticketmaster sparked outrage in November 2022 when its site crashed during a presale event for a Taylor Swift tour.
The company said the site was overwhelmed by both fans and attacks from bots, which were posing as consumers to scoop up tickets and sell them on secondary sites.
At the time, the superstar criticised Ticketmaster on social media, saying it was “excruciating for me to just watch mistakes happen with no recourse” after Swift’s fans reported long wait times and site outages during the presales.
The debacle prompted congressional hearings aimed at better protecting consumers.