In text messages to customers and on its own website, the payment company warns of fake emails, text messages, phone calls and job offers that purport to come from Klarna.
"Remember that Klarna will never contact you to ask for personal information, login details, passwords, bank or card details, or to verify your account via unknown links," the company writes.
Black Week is one of the biggest sales periods in retail, which means that the number of payment transactions also increases dramatically.
