In a statement Sunday, Beijing warned operators of key infrastructure against buying the company's goods, saying it found "relatively serious" cybersecurity risks in Micron products sold in the country. The components caused "significant security risks to our critical information infrastructure supply chain," which would affect national security, according to the statement from the Cyberspace Administration of China, or CAC.

However, US intelligence sources say that the Micron probe was less about security and more about "pro-retaliation" voices in Beijing who do not like the fact that the US still dominates the chip market, for now. 

However memory chips "aren't usually considered a cybersecurity risk because they don't require any specific software or run code. The Associated Press describes China's move as "stepping up a feud with Washington over technology and security," adding that Chinese officials "appear to be struggling to find ways to retaliate without hurting China's smartphone producers and other industries and efforts to develop its own processor chip suppliers," which import more than $300 billion in foreign chips every year.

The Micron review was announced hours after Japan joined Washington in imposing restrictions on Chinese access to technology to make processor chips on security grounds. Foreign companies have been rattled by police raids on two consulting firms, Bain & Co. and Capvision, and a due diligence firm, Mintz Group.