Small business owners are growing increasingly optimistic about the future, reversing a trend seen between 2012 and 2013.

Slighty more than half of U.S. small businesses (51 percent) reported "positive" feelings about the year ahead, compared to 45 percent in 2011, according to a recent survey from small business insurer Hiscox. The surveyed gathered data on 500 owners or partners of U.S. companies with fewer than 50 employees. 

Factors that may be contributing to the improving sentiment include the declining percentage of customers making late payments to small businesses, which fell from 39 percent in 2011 to 26 percent today, and the percentage of small businesses describing new funding as "difficult to find" which dropped from 74 percent to 65 percent during the past year.

At the same time, however, the threat of hackers is a growing cause of concern among small businesses, with 11 percent reporting fears related to cyber attacks, up from 7 percent in 2013.

While many small business owners consider their companies too small to be targeted by hackers, the size of one's business has little to do with whether or not it's likely to be the victim of a cyber attack. 

"It's about what systems they're using that may be used by other businesses and then are the entrée into a whole bunch of data and potentially customer information and bank account information," says Hunter Hoffmann, head of U.S. communcations at Hiscox. "Look at the Target hack. They're pretty sure that the way [hackers] got into the system was through the HVAC installer."

Despite the rising concern of cyber threats from small businesses, only 6 percent of U.S. respondents reported having e-risks insurance. Some of the expenses associated with being the victim of a cyber attack include repairing security systems, hiring legal representation and notifying customers that may be affected.

"You can also be sued for breach of contract from one of the payment card processing companies or the banks that issue the credit cards," Hoffmann says, adding that two out of three small businesses that are sued end up going out of business within six months due to a lack of resources to pay legal fees.

While small businesses with little or no IT departments are viewed as "weak links" for hackers, companies of all sizes risk being victims of cyber attacks, according to Hoffmann.

"Target had 100 people spending all their time making sure their system didn't get hacked, and it still did," he says. "Unless you do everything with a paper and ledger, you're going to be exposed to this."