PwC's #threatintel team published our reporting on Russia-based TA #BlueCallisto (aka #TAG53 #SEABORGIUM #Callisto). Though they have included Ukrainian targeting in their operations, they've maintained a focus on US government organizations including the US National Labs.

Reporting here:
https://www.pwc.com/gx/en/issues/cybersecurity/cyber-threat-intelligence/blue-callisto-orbits-around-us.html

(Recorded Future also published research on the same actor who they call #TAG53
https://www.recordedfuture.com/exposing-tag-53-credential-harvesting-infrastructure-for-russia-aligned-espionage-operations)

(also posted on the bird site)