network-recon

A network reconnaissance guide for discovering computers, open ports, running services, operating systems, and possible weaknesses on a target network. Reconnaissance is the information-gathering stage of a security assessment.

In plain words
What is it for?
Authorized network assessments, including passive subdomain research, host discovery, port scanning, service fingerprinting, topology mapping, and recording discovered targets.
Why use it?
Testing without first knowing what systems and services exist can miss important entry points or waste effort. The guide starts with passive research and continues through host discovery, service identification, and network mapping.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/ogrodev/fsociety/network-recon
Any agent
npx skills add ogrodev/fsociety --skill network-recon
Clone the repo
git clone --depth 1 https://github.com/ogrodev/fsociety

Made for: Claude Code, Codex.

Per session 314 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,394 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00314 $0.03394
Opus 5 $0.00157 $0.01697
Sonnet 5 $0.00063 $0.00679
Haiku 4.5 $0.00031 $0.00339

Measured 3d ago against content hash 48dd9f145bc9, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

network-recon scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

elliot/skills/network-recon/SKILL.md · 325 lines

How it starts

The opening of the file, as written. The whole thing — 325 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Network Reconnaissance

Network reconnaissance is the systematic process of discovering hosts, mapping open ports, fingerprinting services and operating systems, and identifying vulnerabilities across target networks. It is the foundation of every penetration test -- everything downstream (web testing, exploitation, lateral movement) depends on the quality of your initial network recon.

Reconnaissance Methodology

Follow this sequence. Each phase feeds the next. Skip phases only when scope explicitly restricts them.

Phase 1 -- Passive Reconnaissance

Gather intelligence without sending a single packet to the target. This phase has zero detection risk.

Objectives: Identify IP ranges, ASNs, known services, historical scan data, DNS records.

# Passive subdomain enumeration
subfinder -d target.com -silent -o subdomains.txt

# OSINT-based port data (Shodan, Censys)
# Use ctx_execute or Hexstrike MCP tools for API queries

Integration: Store discovered targets immediately.

node ${CLAUDE_PLUGIN_ROOT}/scripts/target-intel.js add "target.com" network "passive-subdomains" "$(wc -l < subdomains.txt) subdomains found" --source "subfinder"

Phase 2 -- Host Discovery

Determine which hosts are alive before port scanning. Scanning dead hosts wastes time and generates noise.

Tool Selection:

  • Same LAN: ARP scan (most reliable, cannot be firewalled)
  • Remote targets: TCP SYN ping + ICMP + UDP combined
  • Firewall-heavy: TCP ping on known-open ports (80, 443)

Load: ToolSearch -> select:mcp__hexstrike-ai__arp_scan_discovery (LAN targets)

# ARP discovery (local network only)
arp-scan --localnet --interface eth0

# Nmap host discovery combinations
nmap -sn -PE -PP -PS80,443,22 -PU53,161 -T3 10.0.0.0/24    # Standard
nmap -sn -PS80,443,8080,22,25 10.0.0.0/24                    # TCP-only (ICMP blocked)
nmap -sn -PR 10.0.0.0/24                                      # ARP only (local subnet)

See references/host-discovery.md for complete host discovery methodology.

Read the full file on GitHub · 325 lines

Files

What ships with it

7 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 3d ago First seen · 325 lines · 314 tokens per session scan A 48dd9f145bc9

Subscribe to this mod's changes

network-recon is a skill published in the GitHub repository ogrodev/fsociety (20 stars, last pushed 5mo ago), licensed MIT. It adds 314 tokens to every session and 3,394 once invoked, about $0.0016 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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