Qantas said on Wednesday it is contacting customers after a cyberattack targeted a third-party customer service platform that stored the personal data of 6 million customers.

Here’s what you need to know.

What happened?

On Monday June 30, Australia’s largest airline detected “unusual activity” on a third-party platform. It took “immediate steps and contained the system,” according to a statement.

“We are continuing to investigate the proportion of the data that has been stolen, though we expect it will be significant,” Qantas said in that statement. “An initial review has confirmed the data includes some customers’ names, email addresses, phone numbers, birth dates, and frequent-flier numbers.”

The database did not contain credit card, personal financial information, or passport details. In addition, Qantas said that no frequent-flier accounts, passwords, personal identification numbers, or login details were accessed.

The Australian airline giant said it is putting additional security measures in place to further restrict access and strengthen monitoring and detection as it investigates whether the cybercriminal group Scattered Spider is responsible for the attack, according to the Financial Times. The attack comes days after the FBI warned that the group had started to target global airlines.

The warning followed recent cyberattacks on Hawaiian Airlines and Canada’s WestJet, the Financial Times reported. Scattered Spider is thought to have conducted a number of high-profile data breaches, including an attack on U.K. retailer Marks and Spencer.

Qantas Group CEO Vanessa Hudson said the airline was working closely with the federal government’s national cybersecurity coordinator, the Australian Cyber Security Centre, and independent specialized cybersecurity experts.

What should I do if I am a Qantas customer?

The airline said it was contacting all customers affected by the data breach. Customers can contact Qantas’s dedicated support line at +61 2 8028 0534 with any questions.

Qantas by the numbers

Shares of Qantas (ASX: QAN) fell 2.2% on Wednesday after the Australian airline confirmed the cyberattack. The airline, which trades on the Australian Securities Exchange (ASX), has a market capitalization of AU$15.91 billion (US$10.47 billion). In February, it reported its half-year earnings results for the period ending December 31, 2024, with an increase in underlying pretax profits, up 11% to AU$1.39 billion (US$914 million), and earnings per share (EPS) of AU$0.63 (US$0.41), up 21%.