Silver Fox Leverages Signed QN Wallpaper Adware for ValleyRAT Deployment via DLL Sideloading
The threat actor Silver Fox is utilizing a sophisticated delivery chain to deploy the ValleyRAT Remote Access Trojan (RAT) by weaponizing the legitimate, digitally signed QN Wallpaper adware. The attack employs DLL sideloading, where the trusted QN Wallpaper executable is manipulated to load a malicious DLL containing the ValleyRAT payload. This technique exploits the inherent trust placed in digitally signed binaries and leverages common security configurations where users or administrators add known adware to antivirus exclusion lists. Once execution is achieved, the malware provides full remote system control and data exfiltration capabilities while operating under the guise of a legitimate, trusted process.
SLEEPWALKER Backdoor: ESET Management Agent Impersonation and Passive Trigger Evasion
The SLEEPWALKER backdoor targets ESET-managed environments by side-loading a malicious 64-bit dpapi.dll into the ESET Management Agent (ERAgent.exe). To evade detection, the malware maintains a passive in-memory state with no outbound C2 traffic or open ports, activating only upon receiving a specific "magic packet." Once triggered, it executes a proprietary 23-instruction bytecode language, enabling staged file delivery and in-memory code execution. This APT-style approach bypasses traditional network monitoring and antivirus tools by impersonating legitimate system DLLs and utilizing alternative communication channels, including VMware VMCI, to maintain a stealthy presence within the victim's security infrastructure.