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. Scoreboard frozen as of March 26, 2026.

---

Edition Stats

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

---

Scoreboard — Top 10

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

---

Challenge Index

#	Challenge	Category	Difficulty	Points
1	ESP Start	ESP	Easy	100
2	Jnouned Router	ESP	Multi	100+200+300+400
3	CAN Bus Implant	Hardware	Medium-Hard	400
4	Glitch The Wired	Hardware	Medium-Hard	100
5	NAVI I2C Sniff	Hardware	Medium-Hard	442
6	Phantom JTAG	Hardware	Medium-Hard	464
7	Serial Experimental 00	Hardware	Easy	50
8	Signal Tap Lain	Hardware	Easy	100
9	Wired SPI Exfil	Hardware	Medium-Hard	100
10	The Wired	Intro	Easy	80
11	Anesthesia Gateway	IoT	Medium-Hard	495
12	Lain Br34kC0r3 V2	IoT	Hard	150
13	Lets All Hate UART	IoT	Medium-Hard	100
14	Nurse Call	IoT	Easy	50
15	Observe The Wired	IoT	Medium-Hard	499
16	Wired Airwave 013	IoT	Medium	398
17	Accela Signal	Misc	Hard	536
18	LAYER ZERO	Misc	Hard	479
19	Patient Portal	Misc	Medium-Hard	340
20	Cyberia Grid	OT	Medium-Hard	500
21	Operating Room	OT	Medium-Hard	500
22	Protocol Seven	OT	Hard	513
23	Schumann Resonance	OT	Medium	196
24	Tachibana SCADA	OT	Medium-Hard	413

---

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

---

Author: Eun0us — ESPILON CTF 2026