Computer hackers have begun targeting electric and nuclear power plants around the world, as well as other critical infrastructure sites in increasingly audacious attacks, a senior Israeli cyber security expert warned on Thursday.Col. (res.) Dr. Gabi Siboni, director of the Cyber Security Program at the Institute for National Security Studies in Tel Aviv, said the recent “major infiltration of Sony Pictures and news that Home Depot and Target were victims of cyber-attacks affecting millions of customers is the least of the world’s worries.“The disruption and possible infiltration of critical infrastructure is the most severe form of cyber-attack. Such attacks on airplanes or air traffic control towers, for instance, means that hackers could cause accidents, or even paralyze entire flight systems. As of now, this area of capabilities is the exclusive domain of developed states,” he continued.“I strongly believe, however, that the next 9/11 will happen without suicide bombers aboard the plane with box-cutters, but will occur because of a cyber incident perpetrated by a terror organization,” he said.Cyber-attacks are not the exclusive domain of the private sector, he said.“Cyber aggression is widely utilized and has become a basic weapon used in international conflicts. Countries are responsible for attacks on most national infrastructure, and governments across the Western world have understood that they must allocate resources not only to purchase new tanks and aerial defense systems but also in defensive cyber infrastructure,” Siboni said.Comparing close US-Israeli cooperation on the development of missile and rocket defenses such as Iron Dome and Arrow, Siboni said bilateral cooperation on cyber defenses “is far behind as very little cooperation exists. Israeli technology and businesses are struggling to gain foothold in the American federal defense market and are left to operate mainly in the private sector. Cooperation in the field of cyber security has yet to overcome obstacles of suspicion.”Siboni is organizing the fifth annual INSS Defensive Operations and Intelligence Cyber Security Conference and Exhibition, which will be held in Washington on April 27-28.