The warning comes after cyber security minister, Chloe Smith, last week reiterated the Government's commitment to tackle cyber crime.
KPMG's head of information protection and business resilience, Stephen Bonner, said:??"The UK's digital economy accounts for 8% of our GDP, so why organisations are yet to develop a mature approach to cyber security is a question that must be answered.
"It does seem that with our economy in a state of sluggish growth, cyber crime is the one area bucking the trend as a shady growth industry. My worry is that boardrooms up and down the country are only slowly wising-up to the threat and understanding the damage that can be inflicted on operations and reputation if they fail to create the appropriate defences."
Bonner added: "It may be tempting to allow IT to dictate cyber strategy, but to do so is to delegate responsibility for the business's whole security, as well as that of every customer and supplier.
"To my mind, this is a cardinal sin and for boards it is a dereliction of duty," he said.