APT28 Uses Microsoft Office CVE-2026-21509 in Espionage-Focused Malware Attacks

The Russia-linked state-sponsored threat actor known as APT28 (aka UAC-0001) has been attributed to attacks exploiting a newly disclosed security flaw in Microsoft Office as part of a campaign codenamed Operation Neusploit.
Zscaler ThreatLabz said it observed the hacking group weaponizing the shortcoming on January 29, 2026, in attacks targeting users in Ukraine, Slovakia, and Romania, three