Recon — Penetration Testing Reconnaissance

Perform structured reconnaissance against an authorized target, organizing findings into an actionable attack surface map.

Cross-references: osint-recon for the deeper open-source-intelligence pass (people, organizations, historical data) — this skill is the active/passive target-mapping side, osint-recon is the broader investigative side; they pair naturally. web-pentest for the next stage once recon has produced an attack surface map and an authorized target list. owasp-audit for source-code review when you have access to the target's code.

Authorization Check

Before running any commands, confirm:

1. The user has written authorization for the target (pentest engagement, bug bounty program, CTF/lab environment)
2. The target is within the defined scope

If authorization is unclear, ask before proceeding. Never assume authorization.

Methodology

Phase 1: Passive Recon

Gather information without touching the target directly.

DNS enumeration:

• Run dig any $ARGUMENTS for A, AAAA, MX, TXT, NS, CNAME records
• Attempt zone transfer: dig axfr @ns-server $ARGUMENTS
• Enumerate subdomains via certificate transparency:

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

WHOIS and registration: Run whois $ARGUMENTS for registrant, nameserver, and creation date info.

Search engine dorking: Use targeted queries — site:, inurl:, filetype:, intitle: — to find exposed pages, documents, and admin panels.

Technology fingerprinting: Identify frameworks, CMS, server software, and JavaScript libraries from public-facing pages.

Public code repositories: Search GitHub/GitLab for the target's org name, domain, API keys, or internal paths.

Historical data: Check the Wayback Machine for old endpoints, removed pages, and configuration files.

Phase 2: Active Recon (explicit authorization only)

Port scanning:

nmap -sC -sV -oN scan-results.txt $ARGUMENTS

Start with top 1000 ports. Expand to full range (-p-) if needed. Use -Pn if the host appears down but is in scope.

Service enumeration: Based on open ports, probe for version info and default configurations.

Web content discovery:

• Directory bruting with gobuster, feroxbuster, or dirsearch
• Virtual host enumeration
• API endpoint discovery (check /api/, /v1/, /graphql, /swagger.json)

SSL/TLS analysis: Run testssl.sh or sslyze to check for weak ciphers, expired certificates, and misconfigurations.

Phase 3: Analysis

Correlate all findings. Identify the most promising attack vectors and prioritize by:

1. Severity of potential impact
2. Likelihood of exploitation
3. Exposure level (internet-facing vs. internal)

Output Format

Produce a structured recon report:

# Recon Report
## Target: [target]
## Scope: [confirmed scope]
## Date: [date]

### Passive Findings
| Finding | Details | Relevance |
|---------|---------|-----------|

### Subdomains Discovered
- [list]

### Technologies Detected
- [list with versions where identified]

### Active Findings
| Port | Service | Version | Notes |
|------|---------|---------|-------|

### Attack Surface Summary
[Prioritized list of interesting findings with risk assessment]

### Recommended Next Steps
[Ordered list of what to investigate further]

Boundaries

• Stay within the defined scope — never scan adjacent or out-of-scope systems
• Rate-limit aggressive scans to avoid disruption
• Log all commands run for the engagement record
• If you discover evidence of active compromise by a third party, alert the user immediately
• Refuse requests targeting systems without explicit authorization
• Refuse requests for mass scanning of unrelated targets

References

• PTES (Penetration Testing Execution Standard)
• OWASP Testing Guide
• Bug Bounty Methodology (jhaddix/tbhm)