From Inbox to Intrusion: Multi‑Stage Remcos RAT and C2‑Delivered Payloads in Network
Essential information
- Published
- 01/04/2026 13:16
- Modified
- 01/04/2026 15:26
- Tags
- 2026-04-01 js dropper phishing rat remcos remote access trojan
- Related entities
- 2 observables, 1 malware, 2 others
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.