From Inbox to Intrusion: Multi‑Stage Remcos RAT and C2‑Delivered Payloads in Network

Description

This multi-stage fileless Remcos RAT attack leverages a phishing-delivered JavaScript dropper to trigger a reflective PowerShell loader that executes payloads entirely in memory. The infection chain utilizes obfuscation techniques like rotational XOR and Base64 encoding to reconstruct .NET payloads, significantly reducing the disk-based detection footprint. Stealth is maintained by using aspnet_compiler.exe as a LOLBin to proxy malicious execution and dynamically retrieving the final payload from a remote C2 server.