![ESPILON CTF 2026](git-header.png)

# ESPILON CTF 2026 — Official Write-ups

Official write-ups for **ESPILON CTF 2026**, a hardware/IoT/OT themed CTF
set in the *Serial Experiments Lain* universe.

> Challenges remain accessible at [ctf.espilon.net](https://ctf.espilon.net).
> Scoreboard frozen as of **March 26, 2026**.

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## Edition Stats

| Stat | Value |
|------|-------|
| Registered participants | 1 410 |
| Players on scoreboard | 264 |
| Total correct solves | 1 344 |
| Challenges | 25 |
| Categories | 6 |

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## Scoreboard — Top 10

| Rank | Player | Score |
|------|--------|-------|
| 1 | silent | 7 397 |
| 2 | Khalid | 5 903 |
| 3 | 0xkakashi | 5 504 |
| 4 | BRODSKY | 5 500 |
| 5 | s13w00 | 5 500 |
| 6 | mungsul | 5 403 |
| 7 | bridgingdragon | 5 403 |
| 8 | pavel?! | 5 300 |
| 9 | fun88337766 | 5 005 |
| 10 | D4RKCYPH3R | 5 005 |

> Points shown are final decayed values at scoreboard freeze (March 26, 2026).

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## Challenge Index

| # | Challenge | Category | Difficulty | Points |
|---|-----------|----------|------------|--------|
| 1 | [ESP Start](ESP/ESP_Start/README.md) | ESP | Easy | 100 |
| 2 | [Jnouned Router](ESP/Jnouner_Router/README.md) | ESP | Multi | 100+200+300+400 |
| 3 | [CAN Bus Implant](Hardware/CAN_Bus_Implant/README.md) | Hardware | Medium-Hard | 400 |
| 4 | [Glitch The Wired](Hardware/Glitch_The_Wired/README.md) | Hardware | Medium-Hard | 100 |
| 5 | [NAVI I2C Sniff](Hardware/NAVI_I2C_Sniff/README.md) | Hardware | Medium-Hard | 442 |
| 6 | [Phantom JTAG](Hardware/Phantom_JTAG/README.md) | Hardware | Medium-Hard | 464 |
| 7 | [Serial Experimental 00](Hardware/Serial_Experimental_00/README.md) | Hardware | Easy | 50 |
| 8 | [Signal Tap Lain](Hardware/Signal_Tap_Lain/README.md) | Hardware | Easy | 100 |
| 9 | [Wired SPI Exfil](Hardware/Wired_SPI_Exfil/README.md) | Hardware | Medium-Hard | 100 |
| 10 | [The Wired](Intro/The_Wired/README.md) | Intro | Easy | 80 |
| 11 | [Anesthesia Gateway](IoT/Anesthesia_Gateway/README.md) | IoT | Medium-Hard | 495 |
| 12 | [Lain Br34kC0r3 V2](IoT/Lain_Br34kC0r3_V2/README.md) | IoT | Hard | 150 |
| 13 | [Lets All Hate UART](IoT/Lets_All_Hate_UART/README.md) | IoT | Medium-Hard | 100 |
| 14 | [Nurse Call](IoT/Nurse_Call/README.md) | IoT | Easy | 50 |
| 15 | [Observe The Wired](IoT/Observe_The_Wired/README.md) | IoT | Medium-Hard | 499 |
| 16 | [Wired Airwave 013](IoT/Wired_Airwave_013/README.md) | IoT | Medium | 398 |
| 17 | [Accela Signal](Misc/Accela_Signal/README.md) | Misc | Hard | 536 |
| 18 | [LAYER ZERO](Misc/LAYER_ZERO/README.md) | Misc | Hard | 479 |
| 19 | [Patient Portal](Misc/Patient_Portal/README.md) | Misc | Medium-Hard | 340 |
| 20 | [Cyberia Grid](OT/Cyberia_Grid/README.md) | OT | Medium-Hard | 500 |
| 21 | [Operating Room](OT/Operating_Room/README.md) | OT | Medium-Hard | 500 |
| 22 | [Protocol Seven](OT/Protocol_Seven/README.md) | OT | Hard | 513 |
| 23 | [Schumann Resonance](OT/Schumann_Resonance/README.md) | OT | Medium | 196 |
| 24 | [Tachibana SCADA](OT/Tachibana_SCADA/README.md) | OT | Medium-Hard | 413 |

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## Categories

| Category | Description |
|----------|-------------|
| **ESP** | ESP32 firmware — flashing, UART, WiFi, custom protocols |
| **Hardware** | Bus interfaces — UART, I2C, SPI, JTAG, CAN, signal decoding, voltage glitching |
| **Intro** | Entry point — ESPILON bot C2 infrastructure |
| **IoT** | IoT protocols — MQTT, CoAP, UART, SDR/FSK |
| **Misc** | Mixed — signal processing, web exploitation, multi-pivot |
| **OT** | Industrial protocols — Modbus, BACnet, OPC-UA, EtherNet/IP |

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*Author: Eun0us — ESPILON CTF 2026*
