China-Linked UAT-8099 Targets IIS Servers in Asia with BadIIS SEO Malware
Jan 30, 2026
Server Security / Cyber Espionage
Cybersecurity researchers have discovered a new campaign attributed to a China-linked threat actor known as UAT-8099 that took place between late 2025 and early 2026. The activity, discovered by Cisco Talos, has targeted vulnerable Internet Information Services (IIS) servers located across Asia, but with a specific focus on targets in Thailand and Vietnam. The scale of the campaign is currently unknown. "UAT-8099 uses web shells and PowerShell to execute scripts and deploy the GotoHTTP tool, granting the threat actor remote access to vulnerable IIS servers," security researcher Joey Chen said in a Thursday breakdown of the campaign. UAT-8099 was first documented by the cybersecurity company in October 2025, detailing the threat actor's exploitation of IIS servers in India, Thailand, Vietnam, Canada, and Brazil to facilitate search engine optimization (SEO) fraud. The attacks involve infecting the servers with a known malware referred to as BadIIS. The hacking gro...