Turning Conference Swag into Pentesting Tools

Published on January 17, 2026 • 10 min read

The Hidden Potential of "Badge-ware"

Have you ever looked at a piece of conference hardware and wondered if it was good for anything more than collecting dust? While searching for microcontrollers for a new project, I rediscovered an old badge powered by the ESP32S3 WROOM-1. This little chip is more than just a novelty; it’s a fully capable IoT development platform with Wi-Fi, Bluetooth, and native USB HID support.

In this post, we’ll look at how to identify components on a mystery board and transform it into a functional hardware password manager or a "remote evil keyboard."

Step 1: Mapping the Hardware

Before writing code, you have to understand the pinout. On this particular badge, the OLED screen was labeled with Ground, VCC, SCL (Clock), and SDA (Data), but we didn't know which ESP32 pins they mapped to.

Using the continuity test (the "beep" function) on a multimeter, I traced the paths from the screen headers and the physical buttons back to the microcontroller pins:

  • SDA (Data): Pin IO 8
  • SCL (Clock): Pin IO 9
  • Button A (Cycle): Pin IO 35
  • Button B (Type): Pin IO 36
// Identification tip: Always check the data sheet for // your specific chip (e.g., QFN-56 layout) to verify // your multimeter findings.

Project: Hardware Password Manager

The goal was to solve a human problem: remembering 64-character high-entropy passwords. Since the ESP32S3 can masquerade as a USB HID (Human Interface Device), the computer sees it as a standard keyboard.

I programmed an Arduino sketch that allows the user to cycle through entries on the OLED screen using one button and then "type" the selection into the host computer with the other. No drivers required, and it bypasses the need for clipboard-stealing malware to worry about.

Taking it Further: The Remote Web Keyboard

Being penetration testers, we have to see if we can use this for "evil." By running an Async Web Server on the badge, we can bridge the gap between Wi-Fi and USB.

We can plug the badge into a target computer and access the badge's IP from our own device. Anything typed into the web interface is translated into hardware keystrokes on the target. This turns a simple badge into a remote-access "rubber ducky" style tool.

"It’s like a rubber ducky, but with a web interface. You’re using Computer A to type into Computer B, and the OS just thinks it's a hardware keyboard."

Conclusion

From badge-ware to card snatchers and remote keyboards, the ESP32 ecosystem is incredibly versatile. Whether you're working with a full conference badge or a tiny Seeed Studio Xiao module, these tools are everywhere and capable of far more than their original designers intended. Happy hacking!