recon-phase

A checklist for passive reconnaissance, which means collecting information about a target without actively attacking it. It covers DNS, WHOIS domain-registration records, subdomains, public certificates, IP details, and search-engine queries.

In plain words
What is it for?
Use it at the start of an authorized security engagement to find mail and name servers, subdomains, related IP addresses, certificate names, network ownership, location data, and exposed public files or login pages.
Why use it?
It organizes early research so important public information about a domain or network is less likely to be missed.

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/s0ld13rr/pentestcode/recon
Any agent
npx skills add s0ld13rr/pentestcode --skill recon
Clone the repo
git clone --depth 1 https://github.com/s0ld13rr/pentestcode

Made for: Claude Code, Codex.

Per session 35 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 592 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. 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 $0.00035 $0.00592
Opus 5 $0.00017 $0.00296
Sonnet 5 $0.00007 $0.00118
Haiku 4.5 $0.00003 $0.00059

Measured 2d ago against content hash c63ef0cc0891, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

recon-phase scanned grade A with 1 finding 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 2d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -s "https://crt.sh/?q=%25.<domain>&output=json" | jq -r '.[].name_value' | sort -u
skills/phases/recon/SKILL.md · 82 lines

What it actually says

Passive Reconnaissance Checklist

Work through each item. Mark completed in your state updates. Skip items not applicable to the target type.

DNS Enumeration

dig <domain> ANY +noall +answer
dig <domain> MX +short
dig <domain> NS +short
dig <domain> TXT +short
host -t AXFR <domain> <nameserver>   # zone transfer attempt

WHOIS

whois <domain>
whois <ip>

Subdomain Discovery

subfinder -d <domain> -silent -o subdomains.txt
amass enum -passive -d <domain> -o amass_subs.txt
# Merge and deduplicate
cat subdomains.txt amass_subs.txt | sort -u > all_subs.txt

Certificate Transparency

curl -s "https://crt.sh/?q=%25.<domain>&output=json" | jq -r '.[].name_value' | sort -u

Reverse DNS

# For each discovered IP
for ip in $(cat ips.txt); do host "$ip"; done

IP Geolocation & ASN

whois -h whois.radb.net -- "-i origin $(whois <ip> | grep -i origin | awk '{print $2}')"
curl -s "https://ipinfo.io/<ip>/json" | jq .

Google Dorking

Search patterns:

  • site:<domain> filetype:pdf|doc|xls|conf|sql|log
  • site:<domain> inurl:admin|login|wp-admin|phpmyadmin
  • site:<domain> intitle:"index of"
  • site:<domain> ext:env|cfg|ini|bak

Shodan / Censys

shodan host <ip>
shodan search "hostname:<domain>"

Web Archive

curl -s "https://web.archive.org/cdx/search/cdx?url=*.<domain>&output=json&fl=original&collapse=urlkey" | jq -r '.[][]' | sort -u

Technology Detection

whatweb <url> -v
curl -sI <url>   # server headers, X-Powered-By

Phase Completion Criteria

Move to ENUMERATION when:

  • All target domains/IPs identified
  • Subdomains enumerated
  • DNS records collected
  • WHOIS data recorded
  • Technology stack identified where possible
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. 2d ago First seen · 82 lines · 35 tokens per session scan A c63ef0cc0891

Subscribe to this mod's changes

recon-phase is a skill published in the GitHub repository s0ld13rr/pentestcode (566 stars, last pushed 11d ago), licensed MIT. It adds 35 tokens to every session and 592 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.