Australia’s Department of Home Affairs said it was working with Ticketmaster after hackers allegedly stole the personal information of more than 500 million customers.
The ShinyHunters hacking group is reportedly demanding a $500,000 (£400,000) ransom to prevent the information from being sold to other parties.
Australia said it was aware of the breach and “is working with Ticketmaster to understand the incident”.
Ticketmaster, an American website that is one of the world’s largest online ticket sales platforms, has not yet confirmed whether it has suffered a security breach.
Reports show that a group of hackers obtained the names, addresses, phone numbers and some payment details of 560 million Ticketmaster customers around the world.
A spokesman for the US Embassy told AFP that the FBI had provided assistance to Australian authorities.
ShinyHunters has been linked to a series of high-profile data breaches that cost companies millions of dollars.
In September last year, the data of nearly 200,000 Pizza Hut customers in Australia was leaked.
This latest hack coincides with the relaunch of BreachForums, a dark web site where other hackers buy and sell stolen materials and messages to carry out hacks.
According to technology media reports, the FBI launched a crackdown on the domain in March 2023 and arrested its administrator, Conor Brian Fitzpatrick, but the domain was again Reappear.
Users of the forum often exaggerate the scale of their hacks to attract the attention of other hackers.
Individuals who reported large amounts of information in the past have turned out to be repeats of previous hacks, rather than newly stolen information.
But if confirmed, the hack could be the worst breach ever in terms of the amount and scope of the material stolen.
This is not the first time Ticketmaster has encountered security issues.
In 2020, it admitted hacking one of its competitors and agreed to pay a $10 million fine.
The company was said to have been hit by a cyberattack last November, causing problems with ticket sales for Taylor Swift’s Era tour.
Earlier this month, U.S. regulators sued Ticketmaster parent company Live Nation, accusing the entertainment giant of using illegal means to maintain its monopoly on the live music industry.
The DOJ lawsuit alleges that the company’s practices locked out competitors and resulted in higher fares and worse customer service.
The BBC has contacted Live Nation for comment.
