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

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.