In this task we have x86 ELF binary ish, which has been run at 54.208.86.14 9988.
This binary is one more Unix shell, but with few commands avaliable:
There is only two intresting commands: lotto and login.
lotto
Task description gives us only service ip, port (54.165.225.121 and 5333 respectively) and binary, named s3.
We've got the following binary and its source code: xorcise.
$ file xorcise xorcise: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.32, not stripped
Looking attentively at source code you can find this interesting moment in decipher function:
