Grandoreiro, a notorious banking trojan active since 2016 across Latin America, continues operations despite major law enforcement disruption in 2024. Recent campaigns leverage DLL sideloading techniques, abusing the legitimate Duplicate Files Finder application to execute malicious code. The loader incorporates extensive anti-analysis mechanisms including sandbox detection, virtual machine artifact checks, process blacklisting, and environment profiling to evade automated analysis systems. These defensive checks occur before C2 contact, indicating high priority on avoiding detection. Telemetry from June 2026 shows activity concentrated in Latin America, primarily Mexico, with limited presence in Europe and North America. The malware uses custom string obfuscation combining proprietary decryption with Base64 encoding, and communicates with C2 infrastructure over TCP port 6432 using encrypted requests containing host-specific information.
An MDR investigation successfully mapped the complete operational infrastructure of Banana RAT, a Brazilian banking trojan operated by threat cluster SHADOW-WATER-063. The investigation uncovered both server-side and client-side components, revealing a sophisticated FastAPI-based polymorphic payload generation system that produces hash-unique builds to evade detection. The malware employs layered obfuscation, AES-wrapped payloads, and fileless PowerShell execution. Once deployed, it enables operator-driven fraud through remote input control, keylogging, screen streaming, bank-branded overlays, and Pix QR code interception specifically targeting Brazilian financial institutions. The tooling exclusively targets 16 Brazilian banks and crypto exchanges, with all operator artifacts written in Brazilian Portuguese, indicating a financially motivated actor operating within the Tetrade banking trojan ecosystem.
