Only install mobile apps from trusted places, and always double-check the privacy settings to ensure you are not giving away too much information.
Companies you do business with should never ask for your account information, credit card numbers or password in an email. If you have any questions about an email you receive that supposedly came from your financial institution or service provider, find their number on their website and call them.
CEO Fraud is a type of targeted attack. It commonly involves a cyber criminally pretending to be your boss, then tricking or fooling you into sending the criminal highly sensitive information or initiating a wire transfer. Be highly suspicious of any emails demanding immediate action and/or asking you to bypass any security procedures.