Yes you are. Regardless of your structure, if you are engaging in financial transactions involving credit cards, checks, customer information, etc. you are exposed. If you have employees, you are exposed. If you have customers you are exposed. If you have vendors you are exposed.
With the busiest shopping season of the year upon us and a rash of recent increases in the frequency of data breaches, you need to protect your business. How? Obviously you need to be very careful about the security of your data. Also, importantly, I highly recommend you purchase insurance coverage for data breach. Contact your insurance agent to see what is available.