How to Use the Command 'smbmap' (with examples)

Smbmap is a versatile tool designed to assist in the enumeration of SMB (Server Message Block) shares on networks. It allows cybersecurity professionals and network administrators to identify accessible network shares and evaluate file permissions across networks or domains, a critical step in identifying security vulnerabilities or ensuring proper configurations. By employing smbmap, users can systematically analyze shares, inspect permissions, and manage files within SMB shares efficiently.

Enumerate hosts with NULL sessions enabled and open shares

Code:

smbmap --host-file path/to/file

Motivation:

This command is essential for identifying hosts on a network that have NULL sessions enabled, which often indicates weak security configurations. Requiring no authentication, NULL sessions can potentially expose sensitive information. By enumerating these hosts and their open shares, network administrators can quickly determine which systems need to be secured or configured to restrict unauthorized access.

Explanation:

• --host-file path/to/file: This argument specifies the path to a file that contains a list of hostnames or IP addresses. Smbmap will read this file to target multiple hosts for enumeration.

Example Output:

[+] IP: 192.168.1.10:445 Name: HOSTNAME Shares: Documents, Backups [NULLSession]
[+] IP: 192.168.1.12:445 Name: SERVER Shares: Public, Media [NULLSession]
[-] No open shares found on 192.168.1.15:445

Enumerate hosts and check SMB file permissions

Code:

smbmap --host-file path/to/file -u username -p password -q

Motivation:

Checking SMB file permissions is crucial for ensuring that sensitive data is only accessible to authorized users. This command allows administrators to gain insights into which users have specific access rights to files and directories on network shares. By using it, security teams can preemptively identify incorrectly configured permissions, thereby preventing unauthorized data access.

Explanation:

• --host-file path/to/file: Targets multiple hosts specified in the given file.
• -u username: Specifies the username for authentication.
• -p password: Provides the corresponding password for the username.
• -q: This option suppresses banner output, making it easier to focus on permissions data.

Example Output:

[+] IP: 192.168.1.10:445 Name: HOST1 Permissions: Read (Documents), Read/Write (Backups)
[+] IP: 192.168.1.12:445 Name: HOST2 Permissions: No Access (Private), Read (Public)

Connect to an IP or hostname through SMB using a username and password

Code:

smbmap -u username -p password -d domain -H ip_or_hostname

Motivation:

Directly connecting to a specific host is useful for conducting focused security assessments or administrative tasks on known devices. This scenario often comes up when troubleshooting access issues or validating configurations post-deployment. Establishing a connection with specified credentials grants the assessing party access akin to the user whose credentials are used.

Explanation:

• -u username: Specifies the username for authentication.
• -p password: Password for the username.
• -d domain: Indicates the domain to which the credentials belong.
• -H ip_or_hostname: Specifies the IP address or hostname of the target machine for establishing an SMB connection.

Example Output:

[+] IP: 192.168.1.20 (host.domain.com) Accessed as Domain\User
[+] Shares: HR-Docs, Engineering, IT

Locate and download files recursively up to N levels depth, searching for filename pattern (regex), and excluding certain shares

Code:

smbmap --host-file path/to/file -u username -p password -q -R --depth number --exclude sharename -A filepattern

Motivation:

Locating specific types of files across network shares can be a daunting manual task. This command allows administrators to automate the discovery and retrieval of files matching a specific pattern. It’s particularly helpful in searching for outdated, unnecessary, or even malicious files across large network environments, while excluding directories that might house such files.

Explanation:

• --host-file path/to/file: Targets multiple hosts specified in the file.
• -u username: Specifies the user for authentication.
• -p password: Corresponding password.
• -q: Suppresses unnecessary banner output.
• -R: Denotes recursive searching.
• --depth number: Limits the depth of recursive searching to the specified number.
• --exclude sharename: Excludes specific shares from the search, identified by their names.
• -A filepattern: Uses a regex pattern to specify which files to look for.

Example Output:

[+] Located on SERVER: /Documents/Project-Reports/Report-2021-Q4.pdf
[+] Located on SERVER: /Public/Shared/Misc/findme.txt

Upload file through SMB using username and password

Code:

smbmap -u username -p password -d domain -H ip_or_hostname --upload path/to/file '/share_name/remote_filename'

Motivation:

Uploading files via SMB is often required during deployments, updating configurations, or sharing files securely within an organization’s network. This command allows administrators to push files to specific locations on SMB shares, facilitating centralized file management and distribution. It ensures that files are uploaded with appropriate permissions and can be accessed or modified as needed.

Explanation:

• -u username: Specifies the user for authentication.
• -p password: Corresponding password.
• -d domain: Domain associated with the username.
• -H ip_or_hostname: IP or hostname of the target server.
• --upload path/to/file: Path of the file to be uploaded.
• '/share_name/remote_filename': Specifies the destination share and filename on the remote server where the file will be uploaded.

Example Output:

[+] File 'config.xml' uploaded successfully to //192.168.1.25/configurations/config.xml

Conclusion:

Smbmap is a powerful command-line utility that simplifies the task of enumerating and manipulating SMB shares across large networks. Whether assessing potential vulnerabilities, configuring network shares, or managing files, smbmap provides a suite of functions that are indispensable for cybersecurity experts and network admin alike. By utilizing the tool’s flexibility, users can ensure secure, efficient, and accurate network share management.