Masscan is a powerful network scanner designed to conduct extremely fast scans of large networks. Here’s a more detailed overview of its features and capabilities:
- High-Speed Scanning: Masscan is optimized for speed, allowing it to scan large networks in a fraction of the time it would take traditional scanners like Nmap. It achieves this speed through parallelization and asynchronous scanning techniques, enabling it to send and receive packets rapidly.
- Efficiency: Masscan is highly efficient in terms of resource utilization. It can handle scanning tasks involving millions of IP addresses without overloading the system. This efficiency makes it well-suited for scanning large-scale networks, such as those found in enterprise environments or on the internet.
- Flexible Configuration: Masscan offers a wide range of configuration options to tailor scans to specific requirements. Users can specify target IP ranges, ports to scan, packet rate limits, and other parameters to customize the scanning process according to their needs.
- Elevated Privileges: Masscan is typically run with elevated privileges, such as root access, to bypass certain limitations imposed by the operating system’s network stack. This allows it to send and receive packets more efficiently and access lower-level networking functions.
- Nmap Compatibility: Masscan is compatible with Nmap, another popular network scanning tool. Users can run Masscan with the “–nmap” option to output scan results in a format compatible with Nmap. This interoperability allows users to leverage Masscan’s speed for initial reconnaissance and then use Nmap for more detailed analysis and enumeration.
- Open Source: Masscan is an open-source project hosted on GitHub, making its source code freely available for inspection, modification, and contribution by the community. This transparency fosters trust and allows users to verify the tool’s behavior and security.
- Documentation and Community: Masscan is well-documented, with comprehensive usage instructions and examples available on its GitHub repository. Additionally, there is an active community of users and contributors who provide support, share best practices, and contribute to the ongoing development of the tool.
masscan Command Examples
1. Scan an IP or network subnet for port 80:
# masscan [ip_address|network_prefix] --ports [80]
2. Scan a class B subnet for the top 100 ports at 100,000 packets per second:
# masscan [10.0.0.0/16] --top-ports [100] --rate [100000]
3. Scan a class B subnet avoiding ranges from a specific exclude file:
# masscan [10.0.0.0/16] --top-ports [100] --excludefile [path/to/file]
4. Scan the Internet for port 443:
# masscan [0.0.0.0/0] --ports [443] --rate [10000000]
5. Scan the Internet for a specific port range and export to a file:
# masscan [0.0.0.0/0] --ports [0-65535] -output-format [binary|grepable|json|list|xml] --output-filename [path/to/file]
Summary
In summary, Masscan is a high-speed network scanner that excels at quickly scanning large networks with minimal resource overhead. Its efficiency, flexibility, and compatibility with Nmap make it a valuable tool for network administrators, security professionals, and researchers seeking to perform rapid reconnaissance and vulnerability assessment tasks. However, users should exercise caution and ensure compliance with relevant laws and regulations when conducting network scans.