Operation USB Heist: How Keylogger-Infected Devices Enabled $100M Bank Fraud

A daring cyber heist targeting Brazilian financial institutions has exposed critical vulnerabilities in physical device security protocols, with attackers stealing an estimated $100 million using malware-infected USB devices. The operation, dubbed 'USB Heist' by investigators, represents a dangerous convergence of social engineering and endpoint exploitation.

The attack chain began when perpetrators gained physical access to bank branches, strategically planting USB drives modified with both keylogging capabilities and remote access trojans (RATs). When employees inevitably connected these devices—likely believing them to be legitimate peripherals—the malware silently installed itself, capturing login credentials and transaction authorization codes.

Technical analysis reveals the USB devices contained a multi-stage payload:

1. A keystroke logger capturing all keyboard input including security PINs


2. A screen scraper recording transaction verification processes


3. A RAT module establishing persistent C2 connections


4. Credential harvesting tools targeting Brazil's PIX instant payment system

The attackers reportedly timed their operation to coincide with peak transaction periods, using stolen credentials to initiate fraudulent transfers through both traditional banking channels and the PIX platform. Brazil's Central Bank was forced to temporarily suspend certain fintechs' PIX access during containment efforts, later restoring functionality after implementing additional verification measures.

Security experts highlight three critical lessons:

1. Physical device threats remain severely underestimated in financial sectors


2. USB port control policies require urgent reassessment


3. Multi-factor authentication systems must evolve beyond keystroke logging vulnerabilities

The incident has prompted Brazil's banking regulator to issue new guidelines on endpoint device management, including mandatory USB port disabling and hardware-based authentication requirements. Similar attacks could potentially target any industry relying on physical access controls, making this case study relevant for global cybersecurity professionals.