Sodexo Filmology said it had informed the Information Commissioner’s Office and a specialist forensic investigation team.
“We would advise all employees who have used the site between 19th March-3rd April to cancel their payment cards and check their payment card statements,” it said.
“These incidents have been caused by a targeted attack on the system we use to host our Cinema Benefits platform, despite having put in place a number of preventative measures with CREST-approved security specialists.”
It added: “We sincerely apologise for any inconvenience this has caused you and are doing all that we can to provide access to your benefits via alternative means. We will share more information on this with you, or your provider, in the coming days.”
It seems the issue has been going on for several months, with one employee complaining on the Money Saving Expert forum in February that he had been the victim of attempted fraud.