The U.S. National Security Agency has been accused by China to have launched "tens of thousands" of cyberattacks against Chinese network targets in the past few years, reports SecurityWeek. Northwestern Polytechnical University in the city of Xi'an had its networks targeted by the NSA's Office of Tailored Operations, which then took over "tens of thousands of network devices," including servers, network switches, and routers, a report from China's National Computer Virus Emergency Response Center alleged. The TAO has been accused by CVERC of exploiting then-unknown SunOS operating system flaws to facilitate access to network device operations and passwords. The report, which was co-written by Qihoo 360, also claimed that more than 140GB of data have been stolen by the TAO over the years. "We ask the U.S. to provide an explanation and urge them to stop immediately this illegal move," said Chinese Foreign Ministry spokesperson Mao Ning. The NSA has not yet responded to the allegations, which come more than a year after China was accused by the U.S. of perpetrating the widespread Microsoft Exchange attacks that impacted at least 30,000 organizations across the U.S.