Almost 1.5 million Mastercard and Visa customers have had their credit card details compromised following a successful cyber raid on payment processing systems provider Global Payments.
Reports of an attack on the company first surfaced on Friday.
In a subsequent conference call the firm's chief executive Paul Garcia confirmed hackers had successfully broken into the company's card processing systems.
Garcia also clarified that the attack was contained to the company's North American processing systems but said it was too early to confirm the exact number of accounts affected.
"The company believes fewer than 1.5 million card numbers may have been stolen and that the theft is confined to our North American processing system," he said.
He also revealed that the hackers did not manage to get all the data contained on the system, meaning certain core items remain safe from exploitation.
"Importantly, the investigation to date has revealed that the theft involved track two card data only," he added.
"We do not believe that track one card data was taken. We do not believe cardholder names, addresses, social security numbers, consumer banking information was obtained by the criminals."
Despite the company's affirmative messages, Global Payments credit card processors remain blocked by Visa.
Speaking to V3 Visa said it had taken the step as a precautionary measure and added that the breach had not granted the hackers access to its own systems.
"Visa is aware of an announcement from Global Payments that it experienced unauthorised access into a portion of its processing system that may have exposed payment card information from all major card brands," they said.
"There has been no breach of Visa systems, including its core processing network VisaNet."
Global Payments is a Fortune 1,000 company that offers business-to-business purchasing, gift cards, electronic check conversion and check guarantee, verification services.
The attack on its network comes just after PricewaterhouseCoopers (PwC) released its own report highlighting financial services as being particularly vulnerable to cyber attacks.
Cotton seedling freezes to death as Chang'e-4 shuts down for the Moon's 14-day lunar night
Fortnite easily out-earns PUBG, Assassin's Creed Odyssey and Red Dead Redemption 2 in 2018
Meteor showers as a service will be visible for about 100 kilometres in all directions
Saturn's rings only formed in the past 100 million years, suggests analysis of Cassini space probe data
New findings contradict conventional belief that Saturn's rings were formed along with the planet about 4.5 billion years ago