# Install fierce with Homebrew, apt, Nix DNS reconnaissance tool for locating non-contiguous IP space. Version 1.6.0 via Homebrew; verified from local package data. Also installable with debian: sudo apt install fierce. ## Install ```sh sudo av install brew:fierce ``` Additional install commands: ### macOS - Homebrew (100%): ```sh brew install fierce ``` Evidence: local Homebrew formula metadata ### Linux - Debian apt (92%): ```sh sudo apt install fierce ``` Evidence: Debian stable package indexes: fierce from https://deb.debian.org/debian/dists/stable/main/binary-amd64/Packages.xz - Nix (92%): ```sh nix profile install nixpkgs#fierce ``` Evidence: nixpkgs package indexes: pkgs/by-name/fi/fierce/package.nix from https://api.github.com/repos/NixOS/nixpkgs/git/trees/master?recursive=1 ## Package facts - **Package key:** brew:fierce - **Package manager:** Homebrew - **Version:** 1.6.0 - **Source summary:** DNS reconnaissance tool for locating non-contiguous IP space - **Homepage:** - **Repository:** - **Generated:** 2026-08-03T19:37:03+00:00 ## Executables - fierce (alias) ## Install behavior - Bottle: not available ## Freshness - Page generated: 2026-08-03 - Package-manager version: 1.6.0 ## Project history and usage fierce is a DNS reconnaissance command-line tool used to locate non-contiguous IP space and hostnames for a target domain before deeper scanning. ### Project history The modern fierce repository describes the project as a Python 3 conversion of the original fierce tool by RSnake and others at ha.ckers.org. The repository keeps the older Perl script under scripts/fierce.pl, where the banner identifies Fierce v0.9.9 beta dated March 24, 2007 and credits RSnake with threading and additions by IceShaman. The Python rewrite kept the core reconnaissance idea but modernized the packaging and runtime around Python tooling. The README presents pip installation, direct source checkout, Poetry development setup, pytest testing, flake8 linting, and coverage commands. ### Adoption history fierce belongs to the pre-exploitation reconnaissance layer of security tooling. Its README explicitly frames it as a precursor to tools such as nmap, unicornscan, Nessus, and Nikto, because those scanners are more useful once likely IP space and hostnames are known. The supplied package metadata shows fierce packaged beyond Homebrew, including Debian, Ubuntu, and Nix. That distribution footprint fits a small CLI security utility that penetration testers and defenders can install quickly on Unix-like systems. ### How it is used The README examples center on DNS lookups rather than exploitation. Typical use starts with a domain and a subdomain list, then optionally traverses nearby IPs, restricts nearby lookups to selected domains, attempts HTTP connections on discovered names, widens searches across a /24, checks zone-transfer exposure, redirects output to a file, or scans an internal address range against a chosen DNS server. The original description, preserved in the README, is careful about scope: fierce is meant to identify likely targets inside and outside a corporate network through DNS, not to indiscriminately scan the internet or exploit hosts. ### Why package nerds care For package nerds, fierce is a recognizable example of a security tool whose cultural value is larger than its code size: it wraps a focused reconnaissance workflow into a single installable command and carries lineage from the older ha.ckers.org-era Perl security-tool ecosystem into Python 3 packaging. ### Timeline - 2007: The preserved Perl script identifies Fierce v0.9.9 beta dated March 24, 2007. - Python 3 era: The maintained repository describes itself as a Python 3 conversion to simplify and modernize the codebase. - Packaging note: The README documents pip installation and standard Python development commands. ### Related projects - The project documentation positions fierce before tools such as nmap, unicornscan, Nessus, and Nikto in a reconnaissance workflow. Its operating domain also overlaps with DNS zone-transfer testing and subdomain discovery tools. ### Sources - - ## Security Notes narrow executable package without higher-risk signals. - **Geiger risk:** green / low - narrow executable package without higher-risk signals ## Other Package-Manager Records - Debian apt - fierce - 1.6.0-1: normalized package name match | Debian stable package indexes: fierce from https://deb.debian.org/debian/dists/stable/main/binary-amd64/Packages.xz | Domain DNS scanner | https://github.com/mschwager/fierce - Nix - fierce: normalized package name match | nixpkgs package indexes: pkgs/by-name/fi/fierce/package.nix from https://api.github.com/repos/NixOS/nixpkgs/git/trees/master?recursive=1 - Ubuntu apt - fierce - 1.5.0-1: normalized package name match | Ubuntu 24.04 LTS package indexes: fierce from https://archive.ubuntu.com/ubuntu/dists/noble/universe/binary-amd64/Packages.gz | Domain DNS scanner | https://github.com/mschwager/fierce ## Combined YAML source View the package source record on GitHub. [combined/fierce.yml](https://github.com/mxcl/pkgdb/blob/main/combined/fierce.yml) ## Sources - pkg.so package database - Geiger risk classifier - curated package history - pkgdb category and tag curation - external package-manager database matches - cross-ecosystem install command graph