OTX Threat: The extension you never installed: KREMLIN forges Chrome's own integrity checks to steal banking sessions

Brazilian banking malware operation REF9334 has been deploying KREMLIN toolkit since May 2025, targeting Brazilian financial institutions through malicious browser extensions. The operation uses multi-stage JavaScript loaders, custom C++ installers, and exploits Chromium integrity mechanisms by manipulating Secure Preferences and regenerating required HMACs. Infrastructure leverages Ethereum smart Sectors: Finance