Pragyan_CTF 2017 Writeup

Pragyan_CTF 2017 Writeup.md

Game starts here

• It was just kind of bonus prob.
• Flag: pragyanctf{HelloWorld}

Look harder

• You can get png file at here
• I think it's in wrong category, it's more similar with steganography
• If you open png file, you can see QR-code. However QR-code is not clear and Smart phone application can't read it.
• So if you change yellow color to black you can get flag

Interstella

• You can get png file at here
• Also I think this is steganography problem.
• If you open png file, strange image is shown. If you look pictures carefully, you can see a letter.
• Letter is written with color (196, 196, 196) so if you change another colors to black,
• you can get flag

Roler Coaster Ride

• You can get elf file at here
• If you run program with gdb(gdb-peda) you can see mov, mov, xor command is repeated.
• Every end of xor command rax has ascii letter. If you join all letters you can get flag

Shane and the binary files

• You can get class files at here
• I couldn't solve this problem because I don't have to solve it.
• You can see 3 class files and if you decomplie it then you can see java code.
• I guess program run 4~5 command line program, get passwd and compare it with user input.
• If you can appropriate command to get passwd or you can successfully convert class to java source,
• you can get flag