duksctf

Bunch of sec. enthusiasts who sometimes play CTF

Ph0wn 2018 - Plot

A file was given with instruction matching G-code instructions. Render the file gave the flag.

Description

Plot

Aliens have tried to communicate with us! I’m sure of it! Look: they have sent us an extremely strange file. Can you help us understanding its meaning? What format is it? I hope it is a message of peace!!!

strange.file: SHA256 afe71bd0aa06dfeff51a4c45695e9268ab4fe387b420125f509c9b17a1e7ef5b

Author: cryptax

Details

Points: 500 (no-equipment easy)

Solution

A file with instructions inside was given:

$ $ more strange.file 
M190 S56
M104 S210
M109 S210
M82 
G28 
G1 Z15.0 F6000 
G92 E0
G1 F200 E3
G92 E0
G92 E0
G1 F2700 E-3
M107
G0 F5400 X31.945 Y72.424 Z0.3
G1 F2700 E0
G1 F900 X32.709 Y72.159 E0.03833
G1 X33.495 Y71.971 E0.07663
G1 X34.296 Y71.861 E0.11495
G1 X35.103 Y71.832 E0.15322

After searching we found that it matches G-code. We plot it on ncviewer.com and we got the flag:

Written on December 14, 2018