All accounts point to Chinese spies being the suggested 'nation-state actors' in this press conference. We'll see, as it starts in a couple minutes.
The US-China relationship is heading towards an irreparable state and there's even rumours that tik-tok could be banned.
Update: The US is accusing 2 suspected Chinese intelligence officers of working to obstruct a criminal probe of a "global telecommunications company" in China by cultivating a relationship/bribing a law enforcement employee to be a "double agent" since 2017, per unsealed court docs.