A recent cyber campaign by SilverFox targeted a Japanese manufacturer utilizing advanced techniques such as DLL sideloading, kernel drivers, and resilient persistence mechanisms with ValleyRAT. The attack begins with phishing emails and exploits two previously undocumented Windows applications to sideload a malicious DLL. This DLL, PDFCORE8.dll, contains multiple dangerous components and employs a modular framework, allowing it to switch between drivers to evade detection.
The malware includes a recovery architecture that ensures continuous operation even if components are disrupted. Detection strategies should focus on behavioral patterns rather than singular indicators to disrupt this sophisticated attack.