Nmap vs Sherlock Forensics Port Scanner

Nmap is a free, open-source utility for discovering networks and auditing security. It uses raw IP packets to identify available hosts, services and versions, operating systems, and packet filters or firewalls. Scanning options include TCP and UDP ports, OS and version detection, and ping sweeps. Network administrators can use it to inventory systems, plan service upgrades, and monitor host or service uptime. The Nmap Scripting Engine runs bundled or user-written scripts in parallel for networking tasks such as discovery and vulnerability checks. The suite also includes Zenmap, a graphical interface and results viewer; Ncat for data transfer and debugging; Ndiff for comparing scan results; and Nping for packet generation and response analysis. Most port-scan types require privileged access to send and receive raw packets, although unprivileged users can run connect and FTP bounce scans. Nmap is not a comprehensive vulnerability scanner. End-user use is free, but redistribution in commercial products requires an OEM license. Quarterly OEM licenses start at $9,980.00 per 3 months for eligible small or startup companies.

Sherlock Forensics Port Scanner is a free desktop GUI tool for identifying exposed TCP ports and the services behind them. It scans the top 1,000 TCP ports by default, accepts custom port and CIDR ranges, and can scan all 65,535 TCP ports. For open ports, it retrieves service banners to identify software and version strings. Scans use TCP connect with the full three-way handshake; SYN scans are not supported. Results export to CSV with timestamps, target host, port, protocol, state and service identification. Each export includes an Ed25519-signed sidecar with the CSV’s SHA-256, signature, per-installation public key and UTC timestamp. The scanner identifies ports and services but does not check results against CVE databases or attempt exploitation. It runs on Windows and Linux. Version 0.1.7 supports 64-bit Windows 10/11 as a single executable without installation dependencies or elevated privileges; the native Linux x64 binary requires libgtk-3, libfontconfig1 and libxkbcommon. The free plan has no trial period, feature restrictions or expiry.