Chinese hacking of corporate and government networks in the U.S. and other countries appears to be declining, according to computer-security experts at companies hired to investigate these breaches. ENLARGE The U.S. government has long accused Chinese hackers of widespread espionage into both corporate and government networks. PHOTO: REUTERS The drop-off is stark and may date back two years. Hackers operating out of China were linked to between 50 and 70 incidents that the cybersecurity company FireEye Inc. was investigating on a monthly basis in 2013 and the early part of 2014, said Laura Galante, the company’s director of global intelligence. Starting in October 2015, however, this tally dropped below 10 incidents and hasn’t recovered, she said. “We saw this decline start in 2014 and then another dip in 2015,” she said. FireEye rival CrowdStrike Inc. says that it, too, has noticed a drop in China-based hacking incidents. Chief Technology Officer and co-founder Dmitri Alperovitch said the decline occurred this year and may be caused by a sweeping reorganization of China’s military, announced earlier this year. “I would not necessarily assume that this is a long-term trend,” he said. RELATED FireEye Report: Redline Drawn: China Recalculates Its Use of Cyber Espionage President Xi Jinping’s Most Dangerous Venture Yet: Remaking China’s Military (Apr. 25) Mandiant’s APT1 Report: Exposing One of China’s Cyber Espionage Units Why One Cybersecurity Firm Says China Has Soured on Conventional Hacking (Apr. 22) Chinese Executive Pleads Guilty to Hacking U.S. Defense Contractors (Mar. 24) FireEye thinks the decline started earlier and resulted from multiple factors, including public scrutiny and pressure from the U.S. government. The U.S. government has long accused Chinese hackers of widespread espionage into both corporate and government networks. In 2013, security researchers at Mandiant, later acquired by FireEye, published a report detailing a widespread computer-espionage campaign, called “APT1,” that the company linked to the Chinese military. The U.S. government ramped up the pressure in 2014, when it indicted five Chinese military officers on charges of hacking into U.S. companies to steal trade secrets. None of those charged has appeared in the U.S. In March, Su Bin, a Chinese aviation executive, pleaded guilty to cyberespionage charges for attempting to steal data on Boeing Co.’s C-17 Globemaster III aircraft. Ahead of a visit to the U.S. by Chinese President Xi Jinping in September 2015, news leaked that President Barack Obama was considering sanctions against Chinese companies that benefited from hacking. China’s top security czar flew to Washington to hammer out an agreement, later announced by the two presidents, that China would stop supporting cyberespionage for commercial purposes.