Shares in International Airlines Group, the owner of British Airways, dropped more than 4 per cent at the open on Friday, after the airline revealed a massive data breach affecting thousands of customers.
BA said on Thursday that the card details of 380,000 customers had been stolen in a breach that took place between 21 August and 5 September.
Affected customers have been advised to contact card providers.
The airline said the stolen data did not include travel or passport information, and said: “The breach has been resolved and our website is working normally.”
BA boss Alex Cruz told the BBC: “There was a very sophisticated, malicious criminal attack on our website.”
He also said that the hackers had enough data to use the cards affected.
“"We know the information that has been stolen is name, address, email address, credit card information, that would be credit card number, of course expiration and the three letter code on the back of the credit card...
“No itinerary information, no frequent flyer data, no passport data has been compromised.”
The company is likely to face claims from customers who either suffer a financial loss as a result of fraud or incur costs from having to 'reboot' their financial settings.
Mr Cruz said: “We are 100% committed to compensating them, period. We are going to work with any customer that may have been... financially affected as a direct result of this attack, and we will compensate them for any financial hardship they may have suffered."
It also faces a potential fine from the Information Commissioner’s Office. A cyber attack on TalkTalk in 2015 which affected fewer than half as many customers resulted in a record £400,000 fine.
The data breach comes just over a year after IAG was rocked by a massive IT meltdown at BA over the May bank holiday weekend in 2017.
A failure in the airline’s computer systems led to chaos for passengers over several days, with thousands of people stranded due to cancelled or delayed flights, and more than £350m was wiped off IAG’s market value as a result.
