Passive OS Fingerprinting

Leetha – passive network fingerprinting and analysis engine

Leetha is a passive network fingerprinting and analysis engine.

It identifies devices on a network by analysing broadcast traffic and protocol exchanges, combining passive observation with optional active service probing to build a device inventory, detect anomalies, and map the attack surface.

This is free and open source software.

Key Features

  • Passive-first device discovery without agents, credentials, or device cooperation.
  • Optional active probing for deeper service and protocol identification.
  • Multi-evidence fingerprinting with weighted confidence scoring.
  • Uses protocol sources such as DHCP, mDNS, TCP/IP fingerprints, TLS fingerprints, service banners, and MAC vendor data.
  • Captures device hostnames, service ports, model names, and other identity clues.
  • Infrastructure-aware filtering to reduce noisy multicast-derived results.
  • Device inventory with analyst-editable owner, location, criticality, tags, and notes.
  • Includes CLI tools and a web dashboard.
  • Attack surface analysis, spoofing detection, and presence monitoring.

Website: github.com/tjnull/leetha
Support:
Developer: tjnull
License: GNU General Public License v3.0

Leetha is written in Python. Learn Python with our recommended free books and free tutorials.


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