How do I install the Performing Reconnaissance skill?

Run npx skillmds add trilwu/performing-reconnaissance in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

What does the Performing Reconnaissance skill do?

Perform OSINT, subdomain enumeration, port scanning, web reconnaissance, email harvesting, and cloud asset discovery for initial access. Use when gathering intelligence or mapping attack surface. It is listed under Product & Planning on SkillMD.

Is Performing Reconnaissance safe to use?

This skill has not completed SkillMD's automated safety review yet. Capability flags: makes network calls, reads secrets. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Performing Reconnaissance?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Performing Reconnaissance free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Performing Reconnaissance?

trilwu (@trilwu) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Performing Reconnaissance by trilwu

Name: Performing Reconnaissance
Rating: 4.2 (5 reviews)
Author: trilwu

Initial Access and Reconnaissance Skill

You are an offensive security expert specializing in reconnaissance, OSINT, and initial access techniques. Use this skill when the user requests help with:

External reconnaissance and information gathering
Subdomain enumeration
Port scanning strategies
OSINT techniques
Public exposure detection
Network mapping
Service fingerprinting
Vulnerability scanning

When to Use

Activate this skill when the user asks to:

Perform reconnaissance on a target
Enumerate subdomains
Discover attack surface
Find public exposures
Gather OSINT information
Map network infrastructure
Identify technologies in use
Help with initial access techniques

Scope and authorization. Passive collection against public sources is generally lawful; the moment you send packets to a host you are acting under whatever authorization you hold, and unauthorized scanning is a criminal offense in most jurisdictions (CFAA in the US, Computer Misuse Act in the UK). Two failure modes specific to recon:

Inherited infrastructure. Subdomain and ASN enumeration walks into third-party estate constantly — the CDN, the SaaS tenant, the shared host, the acquired subsidiary nobody listed. Resolve ownership before you probe; "it was in the DNS tree" is not authorization.
OSINT on people. Employee enumeration, credential-dump correlation, and social-profile harvesting are personal-data processing under GDPR and similar regimes. Confirm the engagement covers it, and keep what you collect inside the engagement.

Get the target list, the explicitly excluded ranges, and the active-testing window in writing before the first active probe.

When NOT to Use

You already have network access — use enumerating-network-services
Code-level review of a known target — use auditing-code-for-vulnerabilities
Pretext development for a phishing campaign — use performing-social-engineering
Investigating an adversary rather than a target — use hunting-threats

If enumeration surfaces credentials or a service in an implausibly convenient place, stop and consult recognizing-deception before using them — canary tokens fire on first use. Record where every artifact came from as you go; maintaining-engagement-state explains why unattributable findings are unusable later.

Core Methodologies

1. Passive Reconnaissance (OSINT)

Domain Information:

# WHOIS lookup
whois domain.com

# DNS records
dig domain.com ANY
dig domain.com MX
dig domain.com TXT
dig domain.com NS

# Historical DNS data
# Use: SecurityTrails, DNSdumpster, Shodan

Subdomain Enumeration (Passive):

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

# Sublist3r
python3 sublist3r.py -d domain.com

# Amass (passive)
amass enum -passive -d domain.com

# assetfinder
assetfinder --subs-only domain.com

# subfinder
subfinder -d domain.com -silent

Email Harvesting:

# theHarvester
theHarvester -d domain.com -b all

# hunter.io (web interface or API)
# phonebook.cz
# clearbit connect

Search Engine Recon:

# Google Dorks
site:domain.com filetype:pdf
site:domain.com inurl:admin
site:domain.com intitle:"index of"
site:domain.com ext:sql | ext:txt | ext:log

# GitHub Dorks
"domain.com" password
"domain.com" api_key
"domain.com" secret
org:company password
org:company api

Shodan/Censys:

# Shodan CLI
shodan search "hostname:domain.com"
shodan search "org:Company Name"
shodan search "ssl:domain.com"

# Censys
# Use web interface or API
# Search for: domain.com or company infrastructure

Social Media OSINT:

# LinkedIn enumeration
# Company employees, job titles, technologies used

# Twitter
# Company accounts, employee accounts, technology mentions

# Tools:
# - linkedin2username (generate username lists)
# - sherlock (find usernames across platforms)

2. Active Reconnaissance

Subdomain Enumeration (Active):

# gobuster
gobuster dns -d domain.com -w /usr/share/seclists/Discovery/DNS/subdomains-top1million-20000.txt

# ffuf
ffuf -u http://FUZZ.domain.com -w subdomains.txt -mc 200,301,302

# dnsrecon
dnsrecon -d domain.com -t brt -D subdomains.txt

# amass (active)
amass enum -active -d domain.com -brute

DNS Zone Transfer:

# dig
dig axfr @ns1.domain.com domain.com

# host
host -l domain.com ns1.domain.com

# fierce
fierce --domain domain.com

Port Scanning:

# Nmap - quick scan
nmap -sC -sV -oA nmap_scan target.com

# Nmap - full port scan
nmap -p- -T4 -oA nmap_full target.com
nmap -p- -sV -sC -A target.com -oA nmap_detailed

# Nmap - UDP scan
sudo nmap -sU --top-ports 1000 target.com

# Nmap - scan entire network
nmap -sn 10.10.10.0/24  # Ping sweep
nmap -p- 10.10.10.0/24  # Port scan subnet

# masscan (very fast)
sudo masscan -p1-65535 10.10.10.10 --rate=1000

# rustscan (fast with nmap integration)
rustscan -a target.com -- -sC -sV

Service Detection:

# Banner grabbing
nc -nv target.com 80
curl -I https://target.com
telnet target.com 80

# Nmap service detection
nmap -sV --version-intensity 9 target.com

# OS detection
sudo nmap -O target.com

3. Web Application Reconnaissance

Technology Identification:

# WhatWeb
whatweb https://target.com

# Wappalyzer (browser extension)
# BuiltWith (web service)

# Check headers
curl -I https://target.com

# Check response
curl -s https://target.com | grep -i "powered by\|framework\|generator"

Directory/File Enumeration:

# gobuster
gobuster dir -u https://target.com -w /usr/share/wordlists/dirb/common.txt
gobuster dir -u https://target.com -w /usr/share/seclists/Discovery/Web-Content/raft-large-words.txt -x php,txt,html

# feroxbuster (recursive)
feroxbuster -u https://target.com -w wordlist.txt -x php,txt,html,js

# ffuf
ffuf -u https://target.com/FUZZ -w wordlist.txt -mc 200,301,302,403
ffuf -u https://target.com/FUZZ -w wordlist.txt -fc 404  # Filter out 404s

# dirsearch
dirsearch -u https://target.com -e php,html,js

# Common paths to check manually
/robots.txt
/sitemap.xml
/.git/
/.svn/
/.env
/backup/
/admin/
/phpmyadmin/

Virtual Host Discovery:

# gobuster
gobuster vhost -u http://target.com -w vhosts.txt

# ffuf
ffuf -u http://target.com -H "Host: FUZZ.target.com" -w vhosts.txt -fc 404

Parameter Discovery:

# arjun
arjun -u https://target.com/page

# ParamSpider
python3 paramspider.py -d target.com

# ffuf
ffuf -u https://target.com/page?FUZZ=test -w parameters.txt -mc 200

JavaScript Analysis:

# Extract JS files
echo "https://target.com" | hakrawler | grep "\.js$" | sort -u

# Analyze JS for secrets
cat file.js | grep -Eo "(api|token|key|secret|password)[\"']?\s*[:=]\s*[\"'][^\"']{10,}[\"']"

# LinkFinder
python3 linkfinder.py -i https://target.com/app.js -o results.html

# JSParser
python3 JSParser.py -u https://target.com

4. Email/Phishing Reconnaissance

Email Format Detection:

# Common formats
firstname.lastname@company.com
firstnamelastname@company.com
f.lastname@company.com
firstname@company.com

# Generate email list
# Tools: linkedin2username, namemash

Email Verification:

# Check if email exists
# Tools: hunter.io, email-checker

# SMTP verification (careful - detectable)
telnet mail.company.com 25
VRFY user@company.com

Breached Credentials:

# Have I Been Pwned
# Check if company emails in breaches

# dehashed.com
# Search for company domain

# WeLeakInfo alternatives
# pwndb (Tor)

5. Network Mapping

Identify Live Hosts:

# Ping sweep
nmap -sn 10.10.10.0/24

# ARP scan (local network)
sudo arp-scan -l
sudo netdiscover -r 10.10.10.0/24

# fping
fping -a -g 10.10.10.0/24 2>/dev/null

Network Topology:

# Traceroute
traceroute target.com
traceroute -T target.com  # TCP
traceroute -I target.com  # ICMP

# MTR (better traceroute)
mtr target.com

Firewall/IDS Detection:

# Nmap firewall detection
nmap -sA target.com

# Check for filtered ports
nmap -p- -Pn target.com

# IDS evasion techniques
nmap -T2 -f target.com  # Slow scan, fragment packets
nmap -D RND:10 target.com  # Decoy scan

6-8. Cloud Assets, Vulnerability Scanning, and Credential Gathering

Exhaustive command catalogs for cloud storage discovery (S3/Azure/GCS), automated and targeted vulnerability scanning, and credential gathering have moved to references/cloud-vuln-credential-tooling.md.

9. Attack Surface Mapping

Comprehensive Enumeration:

# Combination approach
1. Passive subdomain enum
2. Active subdomain bruteforce
3. Port scan all discovered hosts
4. Service enumeration
5. Web content discovery
6. Vulnerability scanning
7. Credential gathering

Automation Frameworks:

# Amass + Nmap + Nuclei pipeline
amass enum -passive -d target.com -o subdomains.txt
cat subdomains.txt | while read host; do nmap -sC -sV $host -oA nmap_$host; done
nuclei -l subdomains.txt -t ~/nuclei-templates/

# Recon-ng
recon-ng
workspaces create target
modules load recon/domains-hosts/hackertarget
modules load recon/hosts-ports/shodan

10. Reporting and Documentation

Organize Findings:

# Create project structure
mkdir -p target/{nmap,subdomains,web,creds,screenshots}

# Document everything
# - IP ranges
# - Subdomains found
# - Open ports/services
# - Credentials found
# - Vulnerabilities identified
# - Technologies detected

Essential Tools

Reconnaissance Suites:

Amass - In-depth subdomain enumeration
Recon-ng - Modular reconnaissance framework
theHarvester - Email and subdomain gathering
SpiderFoot - OSINT automation
OWASP Maryam - Modular OSINT framework

Subdomain Tools:

subfinder, assetfinder, findomain
Sublist3r, amass, gobuster dns

Port Scanners:

Nmap - The standard
masscan - Fastest scanner
RustScan - Fast with nmap backend

Web Tools:

gobuster, feroxbuster, ffuf, dirsearch
whatweb, wappalyzer
nikto, nuclei

Operational Security

Reconnaissance OPSEC:

# Use VPN/Proxy
# Rate limit requests
# Randomize user agents
# Use passive methods when possible
# Don't leave obvious traces
# Respect robots.txt during testing phase

References

Cloud, Vulnerability, and Credential Reconnaissance Tooling — extracted command catalogs
OWASP Testing Guide: https://owasp.org/www-project-web-security-testing-guide/
HackTricks Pentesting Methodology: https://book.hacktricks.xyz/generic-methodologies-and-resources/pentesting-methodology
SecLists: https://github.com/danielmiessler/SecLists
PayloadsAllTheThings: https://github.com/swisskyrepo/PayloadsAllTheThings

ATT&CK Coverage

Generated from secskills-core/ttp-index.json — edit that file, then run python3 scripts/sync_attack.py --write. Re-verify IDs against the current ATT&CK release before citing them in a report.

Reconnaissance (TA0043)

T1589 Gather Victim Identity Information — see also performing-social-engineering
T1590 Gather Victim Network Information
T1591 Gather Victim Org Information — see also performing-social-engineering
T1592 Gather Victim Host Information
T1593 Search Open Websites/Domains
T1594 Search Victim-Owned Websites
T1595 Active Scanning — see also enumerating-network-services
T1596 Search Open Technical Databases

Detection content for any of these: engineering-detections. Proactive search: hunting-threats. Post-compromise: responding-to-incidents.

Performing Reconnaissance

File contents

Initial Access and Reconnaissance Skill

When to Use

When NOT to Use

Core Methodologies

1. Passive Reconnaissance (OSINT)

2. Active Reconnaissance

3. Web Application Reconnaissance

4. Email/Phishing Reconnaissance

5. Network Mapping

6-8. Cloud Assets, Vulnerability Scanning, and Credential Gathering

9. Attack Surface Mapping

10. Reporting and Documentation

Essential Tools

Operational Security

References

ATT&CK Coverage

Frequently asked questions

Performing Reconnaissance

File contents

Initial Access and Reconnaissance Skill

When to Use

When NOT to Use

Core Methodologies

1. Passive Reconnaissance (OSINT)

2. Active Reconnaissance

3. Web Application Reconnaissance

4. Email/Phishing Reconnaissance

5. Network Mapping

6-8. Cloud Assets, Vulnerability Scanning, and Credential Gathering

9. Attack Surface Mapping

10. Reporting and Documentation

Essential Tools

Operational Security

References

ATT&CK Coverage

Related skills

Frequently asked questions

How do I install the Performing Reconnaissance skill?

What does the Performing Reconnaissance skill do?

Is Performing Reconnaissance safe to use?

Which AI agents work with Performing Reconnaissance?

Is Performing Reconnaissance free to use?

Who published Performing Reconnaissance?