Rochester, N.Y. - Excellus Blue Cross Blue Shield's cyberattack has some local customers wondering 'what now?'

"I'm very concerned," said Lynda P. Richards. "I didn't realize that I had to because I have an out-of-town provider in Illinois, but they go through Excellus in Rochester first. I just found that out and I'm really glad because I'm going to follow up on all that."

Richards is one of 10 million customers affected. A cyber security expert tells 13WHAM these cyberattacks many times start with company employees unknowingly opening an email and downloading a virus.

"You've got to make sure that all your people from, literally, any employee no matter what their level, what they're status is all the way up to the IT staff to be able to understand and recognize these threats," said Bill Rosenthal, CEO of Logical Operations.

For people like Richards, having your social security, phone numbers and account information compromised is scary. Pete Fenton, a concerned Excellus customer, says he doesn't have much confidence in companies protecting their personal information. "Just seems like no matter what you do your information is out there, doesn't seem like anyone has the ability to protect it, unfortunately," Fenton said.

Excellus is offering two years of free credit monitoring and identity theft protections to its customers. If you believe you've been affected, you can call 1-877-589-3331.