Stegano+ forensic tool + link note:

Stegano tool:
1. outguess ( giấu, lấy lại dữ liệu trong các bit dư thừa của dữ liệu)
sudo apt-get install outguess
outguess -r abc.jpg output.txt
examle: http://linuxpoison.blogspot.com/2010/08/how-to-hide-data-steganography-into.html
Forensic tool default on kalinux :
1. Recover delete file from disk image file:
https://ctftime.org/writeup/1209
2. Audio file analyzer
sonic-visualiser + audacity
http://hyp3rn0vax.blogspot.com/2014/09/su-ctf-2014-hear-with-your-eyes-write-up.html
Classic crypto trick:
1. Poem code
http://hyp3rn0vax.blogspot.com/2014/09/su-ctf-2014-decrypt-message.html
http://www.slideshare.net/derekbruff/poem-codes
Re trick:
ASPacker:
http://hyp3rn0vax.blogspot.com/2014/09/su-ctf-2014-reverse-me-write-up.html