Cathay data hack airlines’ biggest

Cathay Pacific Airways Ltd. became the target of the world’s biggest airline data breach after a hacker accessed credit card, passport and personal details of some 9.4 million customers.

The airline’s shares slumped to the lowest intraday level in nine years, shaving as much as $361 million off its market value, after the Hong Kong-based carrier said it discovered suspicious activity on its network in March and confirmed the unauthorized access in May. Flight safety wasn’t compromised and there was no evidence that any information has been misused, it said, without disclosing details of the origin of the attack.

“This is quite shocking,” said Shukor Yusof, founder of aviation consulting firm Endau Analytics in Malaysia. “It’s probably the biggest breach of information in the aviation sector.”

Affecting more people than the population of Cathay Pacific’s home base of Hong Kong, the hack is in another league of breaches reported by British Airways PLC and Delta Air Lines Inc. this year. Those carriers boosted spending on cybersecurity after hacks, which saw personal and financial information of hundreds of thousands of customers illegally accessed.

“At this point, we believe it is uncertain if Cathay Pacific would be liable to any fines imposed by government authorities for such a breach,” Geoffrey Cheng, an analyst at Bocom International Holdings Co., wrote in a research note Thursday. “However, we expect the share price jitters to linger on for a while.”

The data breach at Cathay — a partner of British Airways in the Oneworld airline alliance — adds to the carrier’s woes, with Chief Executive Officer Rupert Hogg trying to turn it around after two straight annual losses.

“We are very sorry for any concern this data security event may cause our passengers,” Hogg said in a statement on the carrier’s website.