# SpiderLabs/Responder

Responder is a LLMNR, NBT-NS and MDNS poisoner, with built-in HTTP/SMB/MSSQL/FTP/LDAP rogue authentication server supporting NTLMv1/NTLMv2/LMv2, Extended Security NTLMSSP and Basic HTTP authentication.

Repository: https://github.com/SpiderLabs/Responder
Canonical: https://ross.abutalabs.com/products/responder
Language: Python
License: GPL-3.0
License Family: copyleft
Archived: true
Last push: 2020-06-15T18:07:44+00:00

## Health v2 (maintenance only)
Score: 10/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 5061, "days_push": 2270, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, archived
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4890, forks 1804 (observed 2026-08-28T04:09:01.983656+00:00)

## What it is
Responder is a Python-based LLMNR, NBT-NS, and mDNS poisoner with built-in rogue authentication servers (SMB, HTTP/S, MSSQL, FTP, LDAP, POP3, IMAP, SMTP, DNS) that captures NTLMv1/v2, LMv2, and cleartext credentials on a network. This SpiderLabs repository is deprecated; active development continues at lgandx/Responder.

## Use cases
- poison LLMNR and NBT-NS queries during a pentest
- capture NTLMv2 hashes from Windows machines on a LAN
- run a rogue SMB authentication server to collect credentials
- harvest cleartext credentials from FTP, POP3, IMAP, and SMTP
- test network defenses against name-resolution poisoning attacks

## When to choose
- you are conducting an authorized internal network penetration test
- you need to demonstrate LLMNR/NBT-NS poisoning risks to clients
- you want a battle-tested credential-capture tool for red team engagements

## When to avoid
- you want active development or recent fixes - use lgandx/Responder instead
- you need a defensive monitoring tool rather than an offensive one
- you lack explicit authorization to test the target network

## Facets
- artifact type: cli-tool
- maturity: maintenance
- function: security, networking, penetration-testing
- domain: security, penetration-testing, networking
- platform: python, cli
- tags: llmnr, nbt-ns, mdns, credential-harvesting, pentest, smb, ntlm, deprecated, linux, macos

## Member repositories
- SpiderLabs/Responder (main) score 10

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:01.983656+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:18:11.589316+00:00, confidence not recorded.
  - readme: https://github.com/SpiderLabs/Responder (fetched 2026-08-28T04:09:01.983656+00:00, sha fd2e7873ef3f)
- Data as of 2026-08-30T08:39:29.467469+00:00.