If you believe you've been scammed, file your complaint with the FTC, and then visit the FTC's Identity Theft website at ftc.gov/idtheft. Victims of phishing can become victims of identity theft.
Follow the guide below for specific steps to take according to the type of information you shared:
I accidentally sent...my email/username & password/passphrase.
You should... Change your password/passphrase immediately! For your UW username: Call 307 766-4357, option #1 or visit “Change Your UW Domain Password.”
If you're using a free email provider (Gmail, Hotmail, etc) and you find an increasingly and uncontrollable amount of spam, you may wish to change your email address as well. Unfortunately, UW is unable to change your username/email address for spam-reduction purposes.
I accidentally sent...personal information such as: address, bank/financial account number, credit card number or information, answers to security questions, other personal information that can be changed, driver's license/license plate.
You should... While there's no way to "unsend" the email, many of these pieces of information are changeable (especially credit card numbers). Contact the appropriate organization or financial institution. You should also report this as identity theft and take action to protect your accounts.
Please note: the theft of a credit card (or credit card number) alone does not constitute identity theft (as determined by the FTC). You should, however, promptly call the financial institution and have the number changed. You can also work out any erroneous charges on your account.
Also, technically, yes — your address is changeable, if you move. However, consider that only as a last resort; most identity thieves attempt to collect thousands (even millions) of individuals' information during phishing scams; they're likely not singling you out as a target. If you feel your personal safety is threatened, contact your local police department.
I accidentally sent...personal information that isn't changeable -- such as: Social Security number, mother's maiden name, date &/or city of birth, health/medical information.
You should... Unfortunately, there's not much you can do about this except defend yourself (electronically). Visit the FTC consumer information page on Identity Theft and take action to protect yourself. Being proactive and staying alert/aware of your credit is your best defense.
I accidentally sent...University of Wyoming Institutional data -- or data about others to which I have access. Examples include Research data and student/faculty/staff confidential information.
You should... Contact the Risk Management and Safety Division immediately to report the incident.