“ The incident began from June 2025. Multiple independaent security researchers have assessed that the threat acotor is likely a Chinese state-sponsored group, which would explain the highly selective targeting obseved during the campaign.”

How do they know it was a Chinese group or even a state sponsored one?

When you want to spread jingoist paranoia you can just make stuff up and claim any critique is from said actors.

They said "likely", so they don't "know." Yours is the wrong question.

Perhaps it's "...because that would explain..."?

By analyzing payloads / C2 address, etc...