To officially access your bank account online a scammer will need your online banking login information. This is why two-factor or multi-factor authentication is always recommended for online accounts. Even with your login credentials, you’ll have the opportunity to block the login.
To access your bank account through other means, scammers may need your account and routing numbers, security questions and answers, full name, date of birth, your Social Security number, contact information, ATM PIN, and credit or debit card information.