Switch branches/tags
Nothing to show
Find file History
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Permalink
..
Failed to load latest commit information.
README.md

README.md

BCTF CTF 2015: backdoor

Category: Crypto + Programming Points: 600 Solves: 1 Description:

tsh is my favorite backdoor in use. So I forked on github and add some my own functions.

https://github.com/zTrix/tsh/commit/f3ef65cbe8a42995ef9c183fb59de2e2d966a8d5

I’ve setup a tsh client in cb mode, running at 146.148.60.107 7586, with my secret set, and repeatedly ping some important info out.

But very weird someone can steal my info, can you steal it?

You need exploit, crypto, coding, debugging skills, as well as luck and network speed, to solve this challenge.

tip: flag length less than 22( BCTF{} included)

tip2: challenge constant in pel.c not modified

update:

The server running binary has alarm(3) uncommented in tsh.c. link here: https://github.com/zTrix/tsh/commit/f3ef65cbe8a42995ef9c183fb59de2e2d966a8d5#diff-245ad4e8eff2c0fa695986cd7e83dff6R177

Write-up

(TODO)

Other write-ups and resources