Hacked bank account

There are no known viruses in the wild that can infect macOS.

It’s highly unlikely that your card was compromised through your Mac. It’s much more likely that it was skimmed at a point of sale or an online vendor you do business with was compromised.

viv111 wrote:

Thank you for your reply! I know you are right and I'm sure that my Mac would have given me some kind of indication that something was not right. It's just I can't understand how it happened.

Don't confuse (a) your credit card/account and (b) your Mac. Your credit card number can be lifted by any number of places of business where you might have used it. That's not "hacking," it's illegal use of a credit card number by an unauthorized individual. Your original post indicates that you are running 12.6, that is Monterey. The operating system for Monterey is stored on a read-only volume, actually in a snapshot; you can't modify it yourself no matter how hard you try, and certainly no one else can either. The only way to access that MacOS is through an Apple certified and verified installer accessed via Apple's servers, which I expect are pretty unhackable. So the part where you are worrying about a Mac virus is misplaced worry. Your credit card number was probably accessed through an old school stealing that could have been as simple as someone looking over your shoulder or a dishonest employee somewhere. A Mac virus, with the last several iterations of the MacOS, is one of the few things left that you don't need to worry about any more.

I absolutely concur with KiltedTim.

Here is some additional information:

Effective defenses against malware and ot… - Apple Community