Gibberish

DESCRIPTION

NASA receive a weird transmission yesterday but they were't able to decode it. I mean, it's just a bunch of gibberish. The only thing they have cracked was one word "goodbye" They have no clue what that means though. Can you help them?

FLAG FORMAT: dsc{[a-zA-Z0-9_]+}

Solution

• Enter flag.txt contents in cyberchef and base64 decode it

• We see its an ELF executable file

cyberchef

• Copy the contents of the file and base64 decode it using dcode.fr

• Download it to a file

• Now we have an executable

• Changing permissions of the executable and running it

• It asks for a password

• Entering goodbye as password we get flag

• FLAG: dsc{nc_c4n_4ls0_trnsmit_f1les}