Russian APT28 Group Exploits Microsoft Office Vulnerability in *Operation Neusploit* Espionage Campaign

The Russia-linked APT28 group exploited the CVE-2026-21509 vulnerability in Microsoft Office as part of an espionage campaign dubbed Operation Neusploit. Zscaler ThreatLabz detected this activity on January 29, 2026, targeting users in Ukraine, Slovakia, and Romania. The flaw was used for malware-based attacks focused on data exfiltration. No additional technical details about the exploitation or its impact have been provided.