Most serious cyberattacks against the UK now from Russia, Iran and China, cyber chief will say

The head of the U.K.'s National Cyber Security Centre warns that hostile nations like Russia, Iran and China are behind the most serious cyberattacks in the U.K. In a speech Wednesday, Richard Horne will emphasize that British businesses need to prepare for large-scale cyberattacks, especially if the U.K. becomes involved in international conflicts.