"If the thief knew my ID and password, how can I protect my account or phone?: I lost my iPhone 15 Pro few days ago. Then the next day's evening the scam message came. I did not know it was from the thief at that time. So I've entered my ID and passport. Now is it safe if I turn off my lost mode, and change my passport and then again turn on the device?"
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Take out of Lost Mode, but...
You Should Secure your Accounts:
Having been suspiciously scammed, someone may have your credentials. So, do three Things:
A. Re-Associate All Devices:
Disassociate all devices from your Apple Account, first. Sign out of iCloud on all of your devices.. Go here to check the devices associated to your account: Check your Apple ID Device list to See where you're Signed in - Apple Support. Then, log in to your Apple iCloud Account on each device.
B. Verify Your Devices:
Verify that your the devices logged in to your account or officially yours, by using this link: Check your Apple ID Device List to See where you're Signed in - Apple Support
C. Consider Modifying your Credentials:
By all means, consider modifying your credentials, starting with a new password.
D. Change the Password and Passcode: