Bytemancy 0 — PicoCTF 2026

Sending the correct ASCII bytes to a Python program to reveal the picoCTF flag in Bytemancy 0 challenge.

Hello guys!! 👋 PicoCTF 2026 is on and it’s time to shine.

This is a Binary/Forensics challenge worth 50 points.

Description

Can you conjure the right bytes? The program expects specific input bytes and prints the flag when correct.

Connect with netcat:

nc candy-mountain.picoctf.net 55108

Solution

Download or read the program source code (app.py).

The key part:

if user_input == "\x65\x65\x65":
    print(open("./flag.txt", "r").read())

\x65 is ASCII decimal 101, so the program expects:

eee

Side-by-side, with no spaces.

Connect via netcat and send the input:

nc candy-mountain.picoctf.net 55108

Then type:

eee

The program prints the flag.

You can also do it in one line:

printf "eee\n" | nc candy-mountain.picoctf.net 55108

There we go, we have the flag.

Key Takeaway

Understanding ASCII values and hexadecimal bytes is crucial for binary challenges. Decimal 101 = e, so sending eee satisfied the program and revealed the flag.