A China-linked threat cluster leveraged security flaws in Connectwise ScreenConnect and F5 BIG-IP software to deliver custom malware capable of delivering additional backdoors on compromised Linux hosts as part of an “aggressive” campaign.
Google-owned Mandiant is tracking the activity under its uncategorized moniker UNC5174 (aka Uteus or Uetus), describing it as a “former member of Chinese hacktivist collectives that has since shown indications of acting as a contractor for China’s Ministry of State Security (MSS) focused on executing access operations.”
The threat actor is believed to have orchestrated widespread attacks against Southeast Asian and U.S. research and education institutions, Hong Kong businesses, charities and non-governmental organizations (NGOs), and U.S. and U.K. government organizations between October and November 2023, and again in February 2024 using the ScreenConnect bug.
Initial access to target environments is facilitated by the exploitation of known security flaws in Atlassian Confluence (CVE-2023-22518), ConnectWise ScreenConnect (CVE-2024-1709), F5 BIG-IP (CVE-2023-46747), Linux Kernel (CVE-2022-0185), and Zyxel (CVE-2022-3052).