🛠️139,445 SMB

Checklist

• Enumerate Hostname - nmblookup -A [ip]

• List Shares

  • smbmap -H [ip/hostname]

  • echo exit | smbclient -L \\\\[ip]

  • nmap --script smb-enum-shares -p 139,445 [ip]

• Check Null Sessions

  • smbmap -H [ip/hostname]

  • rpcclient -U "" -N [ip]

  • smbclient \\\\[ip]\\[share name]

• Check for Vulnerabilities - nmap --script smb-vuln* -p 139,445 [ip]

• Overall Scan - enum4linux -a [ip]

• Manual Inspection

  • smbver.sh [IP] (port) [Samba]

  • check pcap

Tools

• nmblookup - collects NetBIOS over TCP/IP client used to lookup NetBIOS names.

• smbclient - an ftp-like client to access SMB shares

• nmap - general scanner, with scripts

• rpcclient - tool to execute client side MS-RPC functions

• enum4linux - enumerates various smb functions

• wireshark

Details

Enumerate Hostname

nmblookup

nmblookup -A [IP]

• -A - look up by IP address

Example:

root@kali:~# nmblookup -A [ip]
Looking up status of [ip]
        [hostname]      <00> -         M <ACTIVE>
        [hostname]      <20> -         M <ACTIVE>
        WORKGROUP       <00> - <GROUP> M <ACTIVE>
        WORKGROUP       <1e> - <GROUP> M <ACTIVE>
                        <03> -         M <ACTIVE>
        INet~Services   <1c> - <GROUP> M <ACTIVE>
        IS~[hostname]   <00> -         M <ACTIVE>

        MAC Address = 00-50-56-XX-XX-XX

List Shares

smbmap

smbmap -H [ip/hostname]

This command will show you the shares on the host, as well as your access to them.

Example:

root@kali:/# smbmap -H [ip]
[+] Finding open SMB ports....
[+] User SMB session establishd on [ip]...
[+] IP: [ip]:445        Name: [ip]                                      
        Disk                                                    Permissions
        ----                                                    -----------
        ADMIN$                                                  NO ACCESS
        C$                                                      NO ACCESS
        IPC$                                                    NO ACCESS
        NETLOGON                                                NO ACCESS
        Replication                                             READ ONLY
        SYSVOL                                                  NO ACCESS

If you get credentials, you can re-run to show new access:

root@kali:/# smbmap -H [ip] -d [domain] -u [user] -p [password]
[+] Finding open SMB ports....
[+] User SMB session establishd on [ip]...
[+] IP: [ip]:445        Name: [ip]                                      
        Disk                                                    Permissions
        ----                                                    -----------
        ADMIN$                                                  NO ACCESS
        C$                                                      NO ACCESS
        IPC$                                                    NO ACCESS
        NETLOGON                                                READ ONLY
        Replication                                             READ ONLY
        SYSVOL                                                  READ ONLY

smbclient

echo exit | smbclient -L \\\\[ip]

• exit takes care of any password request that might pop up, since we’re checking for null login

• -L - get a list of shares for the given host

Example:

root@kali:~# smbclient -L \\[ip]
Enter WORKGROUP\root's password:

        Sharename       Type      Comment
        ---------       ----      -------
        IPC$            IPC       Remote IPC
        share           Disk
        wwwroot         Disk
        ADMIN$          Disk      Remote Admin
        C$              Disk      Default share
Reconnecting with SMB1 for workgroup listing.

        Server               Comment
        ---------            -------

        Workgroup            Master
        ---------            -------

Dump All Files

smbclient //10.10.11.236/SYSVOL -U 'MANAGER\operator'
smb: \> recurse on
smb: \> prompt off
smb: \> mget *
smb: \> exit

nmap

nmap --script smb-enum-shares -p 139,445 [ip]

• --script smb-enum-shares - specific smb enumeration script

• -p 139,445 - specify smb ports

Example:

root@kali:~# nmap --script smb-enum-shares -p 139,445 [ip]
Starting Nmap 7.70 ( https://nmap.org ) at 2018-09-27 16:25 EDT
Nmap scan report for [ip]
Host is up (0.037s latency).

PORT    STATE SERVICE
139/tcp open  netbios-ssn
445/tcp open  microsoft-ds
MAC Address: 00:50:56:XX:XX:XX (VMware)

Host script results:
| smb-enum-shares:
|   account_used: guest
|   \\[ip]\ADMIN$:
|     Type: STYPE_DISKTREE_HIDDEN
|     Comment: Remote Admin
|     Anonymous access: <none>
|     Current user access: <none>
|   \\[ip]\C$:
|     Type: STYPE_DISKTREE_HIDDEN
|     Comment: Default share
|     Anonymous access: <none>
|     Current user access: <none>
|   \\[ip]\IPC$:
|     Type: STYPE_IPC_HIDDEN
|     Comment: Remote IPC
|     Anonymous access: READ
|     Current user access: READ/WRITE
|   \\[ip]\share:
|     Type: STYPE_DISKTREE
|     Comment:
|     Anonymous access: <none>
|     Current user access: READ/WRITE
|   \\[ip]\wwwroot:
|     Type: STYPE_DISKTREE
|     Comment:
|     Anonymous access: <none>
|_    Current user access: READ

Nmap done: 1 IP address (1 host up) scanned in 10.93 seconds

Check Null Sessions

smbmap

smbmap -H [ip/hostname] will show what you can do with given credentials (or null session if no credentials). See examples in the previous section.

rpcclient

rpcclient -U "" -N [ip]

• -U "" - null session

• -N - no password

Example:

root@kali:~# rpcclient -U "" -N [ip]
rpcclient $>

From there, you can run rpc commands.

smbclient

smbclient \\\\[ip]\\[share name]

This will attempt to connect to the share. Can try without a password (or sending a blank password) and still potentially connect.

Example:

root@kali:~/pwk/lab/public# smbclient \\\\[ip]\\share
Enter WORKGROUP\root's password:
Try "help" to get a list of possible commands.
smb: \> ls
  .                                   D        0  Thu Sep 27 16:26:00 2018
  ..                                  D        0  Thu Sep 27 16:26:00 2018
  New Folder (9)                      D        0  Sun Dec 13 05:26:59 2015
  New Folder - 6                      D        0  Sun Dec 13 06:55:42 2015
  Shortcut to New Folder (2).lnk      A      420  Sun Dec 13 05:24:51 2015

                1690825 blocks of size 2048. 794699 blocks available

Check for Vulnerabilities

nmap

nmap --script smb-vuln* -p 139,445 [ip]

• --script smb-vuln* - will run all smb vulnerability scan scripts

• -p 139,445 - smb ports

Example:

root@kali:~# nmap --script smb-vuln* -p 139,445 [ip]
Starting Nmap 7.70 ( https://nmap.org ) at 2018-09-27 16:37 EDT
Nmap scan report for [ip]
Host is up (0.030s latency).

PORT    STATE SERVICE
139/tcp open  netbios-ssn
445/tcp open  microsoft-ds
MAC Address: 00:50:56:XX:XX:XX (VMware)

Host script results:
| smb-vuln-ms06-025:
|   VULNERABLE:
|   RRAS Memory Corruption vulnerability (MS06-025)
|     State: VULNERABLE
|     IDs:  CVE:CVE-2006-2370
|           A buffer overflow vulnerability in the Routing and Remote Access service (RRAS) in Microsoft Windows 2000 SP4, XP SP1
|           and SP2, and Server 2003 SP1 and earlier allows remote unauthenticated or authenticated attackers to
|           execute arbitrary code via certain crafted "RPC related requests" aka the "RRAS Memory Corruption Vulnerability."
|
|     Disclosure date: 2006-6-27
|     References:
|       https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-2370
|_      https://technet.microsoft.com/en-us/library/security/ms06-025.aspx
|_smb-vuln-ms10-054: false
|_smb-vuln-ms10-061: 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://technet.microsoft.com/en-us/library/security/ms17-010.aspx
|       https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-0143
|_      https://blogs.technet.microsoft.com/msrc/2017/05/12/customer-guidance-for-wannacrypt-attacks/
|_smb-vuln-regsvc-dos: ERROR: Script execution failed (use -d to debug)

Nmap done: 1 IP address (1 host up) scanned in 5.58 seconds

Overall Scan

enum4linux

enum4linux -a [ip]

• -a - all enumeration

Example output is long, but some highlights to look for:

• output similar to nmblookup

• check for null session

• listing of shares

• domain info

• password policy

• RID cycling output

Manual Inspection

Samba

ngrep is a neat tool to grep on network data. Running something like ngrep -i -d tap0 's.?a.?m.?b.?a.*[[:digit:]]' port 139 in one terminal and then echo exit | smbclient -L [IP] in another will dump out a bunch of info including the version.

rewardone in the PWK forums posted a neat script to easily get Samba versions:

#!/bin/sh
#Author: rewardone
#Description:
# Requires root or enough permissions to use tcpdump
# Will listen for the first 7 packets of a null login
# and grab the SMB Version
#Notes:
# Will sometimes not capture or will print multiple
# lines. May need to run a second time for success.
if [ -z $1 ]; then echo "Usage: ./smbver.sh RHOST {RPORT}" && exit; else rhost=$1; fi
if [ ! -z $2 ]; then rport=$2; else rport=139; fi
tcpdump -s0 -n -i tap0 src $rhost and port $rport -A -c 7 2>/dev/null | grep -i "samba\|s.a.m" | tr -d '.' | grep -oP 'UnixSamba.*[0-9a-z]' | tr -d '\n' & echo -n "$rhost: " &
echo "exit" | smbclient -L $rhost 1>/dev/null 2>/dev/null
sleep 0.5 && echo ""

When you run this on a box running Samba, you get results:

root@kali:~/pwk/lab/public# ./smbver.sh [IP]
[IP]: UnixSamba 227a

When in doubt, we can check the smb version in PCAP. Here’s an example Unix Samba 2.2.3a:

Windows

Windows SMB is more complex than just a version, but looking in wireshark will give a bunch of information about the connection. We can filter on ntlmssp.ntlmv2_response to see NTLMv2 traffic, for example.