Cyber sleuths: Ransom virus under control

WannaCry, a strain of Windows ransomware that posed severe security threats to China's universities and energy corporations, is under control as the number of computers under attack dropped significantly, China's top cybersecurity emergency response center said.

The number of computers in China under attack from the ransomware had dropped Monday to Tuesday to 213,000 per hour on average from more than twice that - 520,000 per hour - from Saturday to Sunday, according to data released by the National Computer Network Emergency Response Technical Team/Coordination Center of China on Wednesday.

"The drop is mainly because users of Windows operating systems have begun to install patches developed by Microsoft after the global attack over the weekend," said Zhang Shuai, an engineer from the center. "But the risk remains high."