This essay appeared as part of around table on how to respond to the SolarWinds attack.

This operation was a tremendous intelligence success for the Russian government, and recovering from it is going to be much harder than people think. It might not even be possible. It requires much more than simply patching the Sunburst vulnerability. It means burning the infected networks to the ground and rebuilding them from scratch, just as you might reinstall your computer’s operating system after a bad virus. But even that won’t be enough.

The Russians were slow and deliberate, using the backdoor in the SolarWinds update to obtain initial footholds in only a few of the 18,000 vulnerable networks, and then working over months to establish persistence by creating alternative means of access that would survive discovery of the initial vulnerability…