British Airways notifies frequent flyers of possible breach of their accounts

Affected users have gathered on the flyertalk.com forum to share their experiences after calling the company's call center, which according to reports, has been giving out "contradictory" information at times.

It seems that the incident is the result of hackers gaining access to a large number of accounts.

A user posted an email message he received from British Airways's Executive Club team saying that the company "has become aware of unauthorized activity" on his account. The Executive Club is the name of BA's frequent flyer program.

"This appears to have been the result of a third party using information obtained elsewhere on the Internet, via an automated process, to try to gain access to your Executive Club account," the email said. "We understand this was login information relating to a different online service which you may have also used to access your Executive Club account."

It is not unusual for hackers to try to access user accounts on multiple services once they obtain a large database of usernames and passwords from a hacked website. That's because many users tend to use a single email address and password to log in on different online accounts, a practice that security experts have long advised against.

According to the BA email message posted on flyertalk.com, the company has changed the passwords for the affected accounts and also, as a precaution, has temporarily suspended their use of Avios. The Avios removal appears on the affected account as a transaction called "Ex-Gratia - Manual Avios Adjustment."

The company has also been responding to affected users on Twitter advising them that their Avios have been suspended as a result of unauthorized activity on their accounts.

In the email posted online, the company said that despite hackers gaining access to accounts, it is not aware of any access to account information pages, flight history or payment card details.

Users who find themselves in this situation and want to spend their Avios are advised to contact their local Executive Club service center to reactivate their accounts.