Each year some toys and gadgets become "it" gifts by virtue of selling out early. Sellers mark up the price – and scammers begin advertising these gifts on bogus websites and social networks, even when they don’t have them.
"Consumers could wind up paying for an item and giving away credit card details only to receive nothing in return," McAfee warns.
One way to be sure an online retailer is legitimate: the Better Business Bureau site and the National Retail Federation's CyberMonday.com, which lists legitimate retailers offering Cyber Monday discounts.