NEW YORK – Leading into the holiday season, hackers are ramping up efforts to attack retailers at the point-of-sale. CNBC reports that BackOff, one of the most effective strands of POS malware that is undetectable by most anti-virus software, saw a huge spike in the third quarter.

The news source continues that BackOff infections increased 57% in August and 27% in September, according to a report by security firm Damballa. Backoff is a new breed of extremely targeted POS malware and is reported to have infected 1,000 businesses, including Kmart and Dairy Queen.

Brian Foster, chief technology officer at Damballa, said it’s likely that cybercriminals will scale up their activity as the holiday season approaches.

"The threat actors are going to be burning the midnight oil trying to get credit card data going into the holiday season," Foster said. "Retailers need to be prepared and diligent in the fourth quarter."

In addition to anti-virus software, businesses should also be using tools to monitor their network traffic to spot potential threats that have already entered their systems so that they can quickly respond, Foster told CNBC.

"A company just using anti-virus is doing below the minimum," he said. "Prevention is never going to be 100%. They need to start detecting what and where the threats already are."