• Masquerade Task Or Service
• File And Directory Discovery
• Asia
• Valleyrat
• Web Protocols
• Eastern Asia
• Obfuscated Files Or Information: Encrypted Or Encoded Data
• Silver Fox
• Scheduled Task
• Rundll32
• Malicious File
• China
• Process Discovery
• Dynamic-Link Library Injection
• Powershell
• File Deletion
• Ingress Tool Transfer
• Reflective Code Loading
• Disable Or Modify Tools
• Regsvr32

New Malware Campaign Targets Chinese-Speaking Users with Winos 4.0

Cybersecurity researchers have uncovered a malware campaign that employs fake software installers disguised as popular applications like LetsVPN and QQ Browser to deliver the Winos 4.0 framework. First identified by Rapid7 in February 2025, the campaign utilizes a sophisticated multi-stage loader called Catena, which operates entirely in memory to evade traditional antivirus detection. The malware, attributed to a threat actor known as Silver Fox, specifically targets Chinese-speaking environments and has been active throughout 2025, adapting its tactics to maintain persistence and avoid detection. The campaign leverages trojanized NSIS installers and is characterized by its careful planning and execution.