The Cyber Grabs CTF Write-up

Raj Upadhyay
2 min readJan 17, 2021

Recently I participated in thecybergrabs CTF.

So let’s see how I was able to solve a few challenges.

Forensic

Jasper

So we have one JPG file. So first thought comes to my mind was to see the image metadata. So I used online metadata and EXIF viewer. (http://metapicz.com/#landing)

Flag:cybergrabs{Y0U_4re_g00d_4t_m3ta_DaT4}

Crypto

W4rm_up

So let’s open the given text file

So as we can see in the in-text file we have ‘$’ and ‘@’ symbols. So first thought that comes into my mind is to convert this ‘@’ to ‘0’ and ‘$’ to ‘1’

so now ciphertext looks like this:

0110001101111001011000100110010101110010011001110111001001100001011000100111001101111011011100010111010101101001011101000011001101011111011001110011000000110000011001000101111101110111001101000111001001101101011101010111000001011111011010010111001101101110001001110111010001011111011010010111010001111101

So now I converted this binary to ‘HEX’ formate which looks like this:

637962657267726162737B71756974335F673030645F7734726D75705F69736E27745F69747D

So next step was to convert HEX into ASCII

Flag:cybergrabs{quit3_g00d_w4rmup_isn’t_it}

Easiest One

So it’s wav file. So listen to it and as soon as I started audio I know it’s Morse Code. So I used the online website to decode Morse-code. (https://morsecode.world/international/decoder/audio-decoder-adaptive.html)

Flag: cybergrabs{1S TH1S A M0RS3 C0D3?}

Thanks for reading.

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Raj Upadhyay

Pursuing M. Tech. in Cyber Security and Incident Response. #LoveToPlayCTF #infosec #cybersecurity