Winsage
May 27, 2026
Research from FortiGuard Labs has identified a phishing campaign that disguises itself as purchase orders, prompting recipients to open harmful attachments. The campaign begins with a phishing email containing a malicious JavaScript file. When executed, this JavaScript decrypts and runs a PowerShell script that uses process hollowing to inject a .NET downloader module into the trusted Windows process MsBuild.exe. This downloader connects to a remote command and control (C2) server to download and execute additional modules, allowing the attacker to alter the malware's behavior after the initial compromise.
The campaign poses significant detection challenges for Windows users due to its use of multiple encryption layers, fileless execution techniques, and process hollowing strategies. Security experts emphasize the need for organizations to enhance their detection capabilities beyond traditional methods, focusing on identifying suspicious activity across various devices and applications. The phishing attack exploits social engineering tactics and blends malicious actions with legitimate administrative tools, complicating detection efforts. Additionally, the human element plays a crucial role in breaches, highlighting the importance of effective communication and collaboration between security teams and other departments to improve security awareness and behavior.
