The attackers has done everything they can to cover their tracks and to plan for long term stay. The best effort now should be building a firewall between the data and attackers so no further damage can be done. That is the product we spend last 5 years to build and ready to go.
Collectively, all security measures and systems at 250 US government agencies and Future 500 companies has failed to detect and stop the attack since as early as March 2020.
End-to-end data protection is the best answer, if not the only answer at the moment. If you can’t be sure the security of the infrastructure, it is natural that you secure the crown jewels the thieves want: data.