p0f

Multi-protocol passive fingerprinting library: TCP/HTTP (p0f-style) + TLS (JA4-style) analysis in Rust

p0f v3 with impersonation spoofing, written in Python - Accurately guess the OS of a packet with passive fingerprinting.

Network Tools

Purely passive OS and application fingerprinting system

modernized and C99 compliant port of p0f (Passive OS fingerprinting)

TCP Fingerprinting of email senders.

Floodspark Counterespionage Firewall (CEF) helps you record and block or honeypot reconnaissance or otherwise illegitimate traffic. CEF is like a web application firewall (WAF) but protects against reconnaissance.

p0f with Python.

Detecting Network Address Translation & Proxy Use

Passive OS fingerprinting support for rspamd

OS Fringerprinting