Apple Pay can be compromised!

That's improbable as your wallet requires authentication to work. It's far more likely your credentials have been compromised for your bank and credit cards, or your Apple ID.

If you think your Apple ID has been compromised - Apple Support

That's a coincidence and not proof that your wallet was compromised. It's far more likely that your credentials were compromised, or your bank, or a merchant with whom you do business.

Donetta:

All credit cards have a certain level of attempted theft.

Occasionally even my own AppleCard wallet - also with advanced fraud protection enabled - shows unknown transactions as well …

… although they usually also have a red “rejected” next to it.

Suggest that you thoroughly review everything about your account at https://appleid.apple.com/ paying particular attention to anything “unknown” … especially your “Trusted Devices” and “Trusted Numbers.”

Yes, I edited my post after a re-read of your OP.

A regular review of https://appleid.apple.com/ is always a wise effort.

Lastly … DON’T SHARE YOUR PASSCODE w/ anyone!!! When passcode knowledge is combined with physical access to your device … a lot of nefarious acts are enabled.

+1