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TryHackMe NerdHerd

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TryHackMe NerdHerd

NerdHerd

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We can see some interesting ports open. Port 21 (FTP) allows anonymous login. Before exploring the website, let’s collect information from the FTP service.

Nmap Scan Results

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PORT     STATE SERVICE     REASON  VERSION
21/tcp   open  ftp         syn-ack vsftpd 3.0.3
| ftp-anon: Anonymous FTP login allowed (FTP code 230)
|_drwxr-xr-x    3 ftp      ftp          4096 Sep 11  2020 pub
| ftp-syst: 
|   STAT: 
| FTP server status:
|      Connected to ::ffff:10.17.86.42
|      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 3
|      vsFTPd 3.0.3 - secure, fast, stable
|_End of status
22/tcp   open  ssh         syn-ack OpenSSH 7.2p2 Ubuntu 4ubuntu2.10 (Ubuntu Linux; protocol 2.0)
| ssh-hostkey: 
|   2048 0c:84:1b:36:b2:a2:e1:11:dd:6a:ef:42:7b:0d:bb:43 (RSA)
|   256 e2:5d:9e:e7:28:ea:d3:dd:d4:cc:20:86:a3:df:23:b8 (ECDSA)
|   256 ec:be:23:7b:a9:4c:21:85:bc:a8:db:0e:7c:39:de:49 (ED25519)
139/tcp  open  netbios-ssn Samba smbd 3.X - 4.X (workgroup: WORKGROUP)
445/tcp  open  netbios-ssn Samba smbd 4.3.11-Ubuntu (workgroup: WORKGROUP)
1337/tcp open  http        syn-ack Apache httpd 2.4.18 ((Ubuntu))
| http-methods: 
|_  Supported Methods: GET HEAD POST OPTIONS
Service Info: Host: NERDHERD; OSs: Unix, Linux; CPE: cpe:/o:linux:linux_kernel

Host script results:
| smb-os-discovery: 
|   OS: Windows 6.1 (Samba 4.3.11-Ubuntu)
|   Computer name: nerdherd
|   NetBIOS computer name: NERDHERD\x00
|   Domain name: \x00
|   FQDN: nerdherd
|_  System time: 2025-08-20T17:57:24+03:00
| p2p-conficker: 
|   Checking for Conficker.C or higher...
|   Check 1 (port 36590/tcp): CLEAN (Couldn't connect)
|   Check 2 (port 58225/tcp): CLEAN (Couldn't connect)
|   Check 3 (port 20635/udp): CLEAN (Failed to receive data)
|   Check 4 (port 20140/udp): CLEAN (Failed to receive data)
|_  0/4 checks are positive: Host is CLEAN or ports are blocked
|_clock-skew: mean: -59m58s, deviation: 1h43m49s, median: -5s
| smb-security-mode: 
|   account_used: guest
|   authentication_level: user
|   challenge_response: supported
|_  message_signing: disabled (dangerous, but default)
| smb2-time: 
|   date: 2025-08-20T14:57:18
|_  start_date: N/A
| nbstat: NetBIOS name: NERDHERD, NetBIOS user: <unknown>, NetBIOS MAC: <unknown> (unknown)
| Names:
|   NERDHERD<00>         Flags: <unique><active>
|   NERDHERD<03>         Flags: <unique><active>
|   NERDHERD<20>         Flags: <unique><active>
|   \x01\x02__MSBROWSE__\x02<01>  Flags: <group><active>
|   WORKGROUP<00>        Flags: <group><active>
|   WORKGROUP<1d>        Flags: <unique><active>
|   WORKGROUP<1e>        Flags: <group><active>
| Statistics:
|   00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00
|   00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00
|_  00:00:00:00:00:00:00:00:00:00:00:00:00:00
| smb2-security-mode: 
|   3:1:1: 
|_    Message signing enabled but not required

alt text

I downloaded the files from the FTP server. However, running exiftool on them did not reveal much information, except for a possible username.

Next, let’s explore the web page.

alt text alt text

We can see there is an /admin directory, which could be useful.

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Logging in or registering as a user does not work, so the only information we can gather here is:

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This encoded text is a rabbit hole.

The only owner name we know is:


I used `enum4linux` to enumerate further.

![alt text](image-2.png)
![alt text](<../assets/images/nerdherd/image copy 9.png>)

We can see a username: `chuck`  
And a shared folder: `nerdherd_classified`

All we need now is a password. I tried brute-forcing, but had no luck.

I was stuck here for a while, so I checked Discord for a hint. The decryption key for `fijbxslz` turned out to be `birdistheword`.

![alt text](<../assets/images/nerdherd/image copy 10.png>)

**Username:** chuck  
**Password:** easypass

Now, let's try logging into the SMB shares.

![alt text](<../assets/images/nerdherd/image copy 11.png>)

After downloading the file, we find:

```bash
┌──(kali㉿kali)-[~/Desktop/tryhackme/tmp]
└─$ cat secr3t.txt                          
Ssssh! don't tell this anyone because you deserved it this far:

    check out "/this1sn0tadirect0ry"

Sincerely,
    0xpr0N3rd
<3

So, we have a directory to check.

alt text

We find new credentials:
chuck : th1s41ntmypa5s

This gives us the SSH password.

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──(kali㉿kali)-[~/Desktop/tryhackme/tmp]
└─$ ssh chuck@10.201.69.156
chuck@10.201.69.156's password: 
Welcome to Ubuntu 16.04.1 LTS (GNU/Linux 4.4.0-31-generic x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

747 packages can be updated.
522 updates are security updates.

Last login: Wed Oct 14 17:03:42 2020 from 22.0.97.11
chuck@nerdherd:~$ ls
Desktop    Downloads         Music                Pictures  Templates  Videos
Documents  examples.desktop  nerdherd_classified  Public    user.txt
chuck@nerdherd:~$ cat user.txt
THM{7fc91d70e22e9b70f98aaf19f9a1c3ca710661be}
chuck@nerdherd:~$

We have obtained the user flag!

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I then uploaded LinPEAS to the machine to continue with privilege escalation.

tryhackme ctf
This post is licensed under CC BY 4.0 by the author.

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