The earlier attack that targeted Microsoft Exchange servers, affecting at least 30,000 organisations globally. Western security services believe it signals a shift from a targeted espionage campaign to a smash-and-grab raid, leading to concerns Chinese cyber-behaviour is escalating.
It began in January when hackers from a Chinese-linked group known as Hafnium began exploiting a vulnerability in Microsoft Exchange. More likely is some criminal group that operates in secret that have been identified.
China has previously denied allegations of hacking and says it opposes all forms of cyber-crime. Witness the move against bitcoin et al.
Linux has its own fair share of security woes. Most miscreants do not waste their time with small shops as there is nothing to gain.