PWK Notes: SMB Enumeration Checklist [Updated]
🚨[Updated for 2024] Check out the latest version of this post here.🚨
[Update 2018-12-02] I just learned about smbmap, which is just great. Adding it to the original post. Beyond the enumeration I show here, it will also help enumerate shares that are readable, and can ever execute commands on writable shares. [Original] As I’ve been working through PWK/OSCP for the last month, one thing I’ve noticed is that enumeration of SMB is tricky, and different tools fail / succeed on different hosts. With some input from the NetSecFocus group, I’m building out an SMB enumeration check list here. I’ll include examples, but where I use PWK labs, I’ll anonymize the data per their rules. If I’m missing something, leave a comment.
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 sharesnmap- general scanner, with scriptsrpcclient- tool to execute client side MS-RPC functionsenum4linux- enumerates various smb functionswireshark
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 established 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 established 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
--------- -------
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.