Hardware Keylogger DIY Blueprint

Hardware Keylogger DIY Blueprint

Complete design for building a USB hardware keylogger:

• PCB Schematic — KiCad design for a USB pass-through device based on ESP32-S2/S3.
• Firmware — Arduino/ESP-IDF code that acts as USB host (receives keyboard input) and USB device (forwards to the PC). Transparent to the OS.
• Storage — Stores keystrokes in SPI flash with timestamps. Capacity of ~1M keystrokes.
• WiFi Exfiltration — Creates a hidden AP or connects to a known network. Web interface for downloading logs.
• Stealth — Physical design that imitates a generic USB adapter. Installs no additional drivers.
• BOM — Bill of materials with links. Total cost ~15 EUR.