How I hacked hackers at LeHack event 2025

Just got back from LeHack, and I figured I'd share a quick write-up of a small PoC I ran during the event.

My Setup:

• 8x ESP32-C3 running custom karma firmware

• 2x M5Stack CardPuters as control interfaces

• SSID list preloaded from Wigle data (targeting real-world networks)

• Captive portal triggered upon connection, no creds harvested, no payloads, just awareness page about karma attack.

• Devices isolated, no MITM, no storage – just a "reminder" trap

Result: 100 unique connections in parallel all over the weekend, including… a speaker on stage (yep – sorry Virtualabs/Xilokar 😅 apologies and authorisation of publication was made).
Plenty of unaware phones still auto-joining known SSIDs in 2025, even in a hacker con.

Main goal was awareness. Just wanted to demonstrate how trivial it still is to spoof trusted Wi-Fi.
Got some solid convos after people hit the splash page.

Full write-up: https://7h30th3r0n3.fr/how-i-hacked-hackers-at-lehack-2025/

For technical details of the Evil-M5project: https://github.com/7h30th3r0n3/Evil-M5Project/wiki

Building tutorial : https://github.com/7h30th3r0n3/Evil-M5Project/wiki/esp32-rig-tutorial

If you were at LeHack and saw the captive-portal or wanna discuss something similar, happy to chat.
Let’s keep raising the bar.

Fun fact : Samsung pushed a update that prevent to reconnect to open network automatically few days ago ! Things change little by little ! ☺️