"Users will come to us and tell us the software's not working so we'll investigate and do an analysis of the software," Paden said. "We also have a brand protection task force that helps us with leads, and finally, we work with other companies and get tips that way too, because if someone's selling fake Microsoft stuff, they're probably selling fake Symantec stuff too."

Symantec encourages that purchases be made through known sellers and also from those who have a "big brand name," Paden advises. Often times, if the price being offered is much lower than the manufacturer suggested retail price, it's probably too good to be true, he adds.

"If the software only comes in a white sleeve and it doesn't come in an official (Symantec) yellow box with documentation, then that's a tell-tale sign that the product's counterfeit," Paden said.