Retail, heath-care and financial services company stocks are the most vulnerable to losses because of cybersecurity problems, said Joe Nocera, a principal at PricewaterhouseCoopers and a cyber-security leader.

At a company Webinar on Wednesday, he noted retailers and health-care businesses are among the most susceptible to cyber threats because these companies have the greatest amount of consumer information.

The PwC expert added financial company stocks also have relatively high downside risk because the businesses have a vast amount of money that crooks can quickly shift out of them electronically.

To hedge against the risk, Nocera said, investors may want to buy shares in businesses offering products and services to protect companies from cyber damage.

Because nearly all companies are being subjected to cyber attacks, Nocera said, corporate America is shifting from an emphasis on prevention to responding quickly and effectively to the intrusions.

He noted most attacks are coming from outside sources, but it is company employees who can do the most damage because they have the greatest access to corporate information.

Nocera said until last year no retailers had seen sales declines from customers staying away because of publicity about cyber incidents. But Target, which cut its outlook Wednesday, acknowledged that the massive data breach of its system has resulted in some shoppers staying away and is one reason its profits have fallen significantly.

Nocera said cyber attacks are clearly having an impact on foot traffic at retailers who have data breaches. He added it is too early to say if customers will continue to stay away because of cyber fears.