U.S. investigators are assessing security risks posed by Bitmain, while Bitmain denies the existence of such risks.

Foresight News reported, citing Bloomberg, that according to sources familiar with the matter, U.S. investigators have been assessing whether products from Bitmain Technologies pose risks of espionage or sabotage. The company denies any such risks. Last year, a federal review highlighted "significant national security concerns" over the use of equipment from Beijing-based Bitmain Technologies Ltd. at locations near military bases. In July this year, a report by the Senate Intelligence Committee again mentioned the company, stating that its equipment could potentially be manipulated by China and poses "several troubling vulnerabilities" to the United States.

According to a U.S. official and six other sources familiar with the matter, Bitmain's hardware devices are at the center of a federal investigation called "Operation Red Sunset." The investigation, led by agents from the Department of Homeland Security, aims to determine whether these machines can be remotely controlled for espionage or to sabotage the U.S. power grid. The official and sources, as well as others describing the federal government's review of Bitmain products, all requested anonymity to discuss this yet-to-be-disclosed investigation. According to a U.S. official and two other sources, in some cases, investigators dismantled Bitmain's machines to test their chips and code for malicious functions. They declined to disclose what, if anything, was found. The official and sources also stated that investigators reviewed potential violations of tariffs and import duties.

In an emailed statement, Bitmain said that claims the company could remotely control its machines from China are "absolutely false." The company stated, "We strictly comply with U.S. and relevant laws and regulations and have never engaged in any activities that would endanger U.S. national security."