On Wednesday, the U.S. Commerce Department included Israel's NSO Group and Candiru on its trade blacklist, alleging that they supplied spyware to foreign governments that used it to target state officials, members of the media, and other people.

Also included were Positive Technologies of Russia and Computer Security Initiative Consultancy PTE LTD of Singapore. They, allegedly, trafficked in cyber tools used to obtain unauthorized access to computer networks, the USCD said.

Because the companies were added to the list for engaging in actions that are harmful to U.S. national security or foreign policy interests, exports from U.S. equivalents are prohibited. It makes it far more difficult for US security researchers to sell them information about computer flaws, for example.

Suppliers will be required to submit an application for a license prior to selling to them, which is almost certain to be denied.

"We're not taking any action against the nations or governments in which these entities are situated," a U.S. State Department representative disclosed.

The NSO Group and Candiru have previously been charged with selling hacking tools to repressive nations. NSO asserts that it offers its products exclusively to law enforcement and intelligence agencies and takes precautions to prevent abuse.

A representative of NSO said the business is "disappointed" by the decision because its technologies "advance U.S. national security objectives and policies by deterring terrorism and criminality," and hence will urge for the decision to be reversed.

The Israeli defense ministry, which licenses NSO for export, refuses to comment on the situation.

NSO will discuss its "rigorous" compliance and human rights policies, "which have already resulted in several terminations of contacts with government agencies that exploited our products," a representative for the company told Reuters in an e-mailed statement.

This year, the Biden administration sanctioned Positive Technologies, a Russian cybersecurity company, for sharing technology to Russian security agencies. Positive Technologies maintains its innocence.

Positive Technologies stated that the new restrictions will have no effect on their operations and will not prohibit the company from going public.

Meanwhile, a former U.S. official acquainted with Positive Technologies, who  asked not to be named, said the company assisted in the establishment of computer infrastructure used in Russian assaults against U.S. businesses.