Recently, Japan Airlines Mileage Bank members got the unfortunate news of a data breach. It’s estimated that hackers may have stolen up to 750,000 pieces of information about Mileage Bank members. JAL is blaming a computer virus from an outside source that infected 12 of JAL’s in-house computer terminals linked to the Mileage Bank program and have been contacting the 190,000 members whose data might have been stolen.

The data that was breached may have included names, addresses (both physical and email), phone numbers, gender, place of work including job titles and JMB membership numbers, but the airline says it has not identified a leak of credit card numbers or passwords. In February, the airline lost millions of yen when hackers penetrated a JAL service that allowed Mileage Bank members to exchange their miles for amazon.com gift cards. The ability to redeem for the gift has been pushed back with this latest event, even though the two do not appear to be related.

Bottom line: As with any online activity that requires a password, it’s advisable to change your password often. If you are a Mileage Bank member, or a member of any frequent flyer program, monitor your account. JAL was proactive with alerting members and has a webpage with information that you can access at http://insideflyerus.wpengine.com/link/?11781 . JAL says that updates will be announced when more information becomes available.