There's two ways this could happen, but neither is super easy:
1) You've handed over your physical debit card and it's PIN code to a baddie and not informed your bank. Unlike the security code on credit cards the PIN code is not on the card. Unlike credit cards you need the actual physical card to transfer money.
2) You've given a baddie your online login info and had him send you a QR code which you then scan and approve the amount.
Notable what does not happen, which does with credit cards, is making a payment at a webshop and that webshop then leaking your card info to a baddie. No one other than the bank ever sees the "secret" part of the card info.
There's two ways this could happen, but neither is super easy:
1) You've handed over your physical debit card and it's PIN code to a baddie and not informed your bank. Unlike the security code on credit cards the PIN code is not on the card. Unlike credit cards you need the actual physical card to transfer money.
2) You've given a baddie your online login info and had him send you a QR code which you then scan and approve the amount.
Notable what does not happen, which does with credit cards, is making a payment at a webshop and that webshop then leaking your card info to a baddie. No one other than the bank ever sees the "secret" part of the card info.