Several credit unions and organizations posted warnings on their Websites. Visa now says the alerts were related to an existing, known payment processor breach. Visa wouldn’t say just what organization or breach it was referring to. It’s unclear what caused all of the confusion about the latest credit card breach warnings, which led to Visa issuing a public statement that there was no new hack. MasterCard, meanwhile, said it is “monitoring developments” in this case and has notified the affected card issuers.”]
Source: https://www.darkreading.com/attacks-breaches/no-new-payment-processor-data-breach-after-all