Tags: misc 

Rating: 0

After playing around with the png for a while using all the normal tools, chucked the png to pngcheck for errors

pngcheck -qv logo.png
File: logo.png (9821 bytes) chunk IHDR at offset 0x0000c, length 13 400 x 180 image, 32-bit RGB+alpha, non-interlaced
CRC error in chunk IHDR (computed baf57a58, expected b65879b0)

Bad CRC found in IHDR so chucked the png at PCRT ( https://github.com/sherlly/PCRT ), fix the errors and restored the correct image height

python PCRT.py -i ../../Documents/liveCTF/radarctf19/misc/logo/logo.png -o ../../Documents/liveCTF/radarctf19/misc/logo/newlogo.png

____ ____ ____ _____
| _ \ / ___| _ \_ _|
| |_) | | | |_) || |
| __/| |___| _ < | |
|_| \____|_| \_\|_|

PNG Check & Repair Tool

Project address: https://github.com/sherlly/PCRT
Author: sherlly
Version: 1.1

[Finished] Correct PNG header
[Detected] Error IHDR CRC found! (offset: 0x1D)
chunk crc: B65879B0
correct crc: BAF57A58
[Notice] Try fixing it? (y or n) [default:y] y
[Finished] Successfully fix crc
[Finished] IHDR chunk check complete (offset: 0x8)
[Finished] Correct IDAT chunk data length (offset: 0xACB length: 1B7A)
[Finished] Correct IDAT CRC (offset: 0x264D): 19ABC7EB
[Finished] Correct IDAT chunk data length (offset: 0x2651 length: 1B7A)
[Finished] Correct IDAT CRC (offset: 0x41D3): 19ABC7EB
[Finished] IDAT chunk check complete (offset: 0xACB)
[Finished] Correct IEND chunk
[Finished] IEND chunk check complete
[Finished] PNG check complete
[Notice] Show the repaired image? (y or n) [default:n] n

With the corrected image we get the flag that was hidden further down the canvas

Flag: radar{hidden_p4rt_looks_smart}