The Russia-linked threat group UAC-0001, also known as APT28, has been actively exploiting a critical zero-day vulnerability in Microsoft Office. The group is using this flaw to deploy sophisticated malware against Ukrainian government entities and European Union organizations. The vulnerability, identified as CVE-2026-21509, was disclosed by Microsoft on January 26, 2026, with warnings about active […] The post Hackers Exploiting Microsoft Office 0-day Vulnerability to Deploy Malware appeared first on Cyber Security News.