China-nexus Armory Castle exploited BeyondTrust Remote Support zero-day CVE-2026-102764 from late August
Mandiant and GTIG attribute exploitation of the critical BeyondTrust Remote Support zero-day CVE-2026-102764 to Armory Castle (formerly tracked as UNC5221), a likely Chinese government-backed espionage group. BeyondTrust dates the first known exploitation to Aug. 29 and says it detected and contained the activity Sept. 28. Only a small nu…