The ESP8266-Powered Masterkey Wi-Fi USB Keylogger Offers Plug-and-Play Capture, Remote Access

Pseudonymous maker "justcallmekoko," who earlier this year published an impressive 255-LED sound-reactive visualizer build, has launched an ESP8266 device with security researchers in mind: the Masterkey Wi-Fi USB keylogger.

"This project was originally inspired by spacehuhn. He created the original Wi-Fi USB Keylogger project using an Arduino Pro Micro/Leonardo and an Arduino Host Shield," Koko explains. "I felt the project deserved some dedicated hardware. With this device, I was able to combine the capabilities of the Wi-Fi USB Keylogger and the Wi-Fi Duck. A lot of the cheap Wi-Fi USB Keyloggers aren't as hackable or as capable. Similar devices that offer these traits can come with a severe price tag. While this may not be as thorough as a CPLD/FPGA based USB Keylogger, it gets the job done."

The device is built around an Espressif ESP8266 microcontroller, and does what you would expect a keylogger to do: A USB keyboard is connected to one end and the other to the host PC, at which point the device begins to log every single keystroke entered onto the keyboard. Koko claims this introduces zero latency, while also offering additional functionality including keystroke injection and remote access to stored keystroke files as well as over-the-air firmware updates via Wi-Fi.

"Masterkey comes with a 3D-printed enclosure to make it less conspicuous," Koko adds. "While layer lines are still visible with FDM printing regardless of layer height, it is better than nothing and I don't know how to do injection moulding. The devices comes fully assembled in its enclosure so first use is as simple as plug and play."

The Masterkey is now on Tindie, priced at $45 including housing; the project has also been published to GitHub.