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June 26, 2026

Reconnaissance & Information Gathering: The Foundation of Every VAPT Engagement

The phase no one talks about enough — and why skipping it ruins everything downstream.

By R. Mahathi

4 min read

What Is Reconnaissance?

Before a penetration tester ever touches a target system, there's a critical phase that happens first: reconnaissance, often shortened to recon. It's the process of collecting as much information as possible about a target — their infrastructure, employees, domains, services, and digital footprint — before any active testing begins.

Think of it like a detective case. You don't walk into a suspect's house without knowing their schedule, routines, and entry points first. Recon is exactly that — building your map before you navigate.

In the VAPT (Vulnerability Assessment and Penetration Testing) lifecycle, reconnaissance is Phase 1. Everything that comes after — scanning, exploitation, post-exploitation — depends entirely on how thorough and accurate your recon was.

Why It Matters

Poor recon = missed attack surfaces = incomplete assessments.

If you don't know about a forgotten subdomain, an exposed employee email, or a misconfigured internet-facing service during recon, you simply won't test it. That blind spot could be the exact thing a real attacker would exploit.

Good reconnaissance:

  • Reveals the true scope of the target's digital exposure
  • Helps prioritize where to focus scanning and testing efforts
  • Reduces noise by giving context to findings
  • Helps avoid tripping alarms by understanding what's out there before touching it

Passive vs Active Recon

This is one of the most important distinctions in this phase.

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Passive reconnaissance means gathering information without directly interacting with the target's systems. You're using third-party sources — public databases, search engines, social media, DNS records — and the target has no way to detect your activity.

Examples: Looking up WHOIS records, searching LinkedIn for employees, using Shodan to find exposed services.

Active reconnaissance involves directly interacting with the target — sending packets, making requests, or querying systems. This leaves traces in logs and can trigger alerts.

Examples: Running Nmap against a target's IP range, enumerating DNS via zone transfers, actively crawling a web application.

During a legitimate VAPT engagement, both types are used — but passive always comes first, and active recon is done within the approved scope window.

OSINT: Open Source Intelligence

OSINT is the art of gathering intelligence from publicly available sources. It's a cornerstone of passive recon.

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Common OSINT sources include:

  • Search engines — Google, Bing, Shodan (for internet-connected devices)
  • Social media — LinkedIn for employee names, roles, and tech stacks; Twitter/X for inadvertent info leaks
  • Public records — WHOIS, DNS registrars, certificate transparency logs
  • Job postings — These often reveal what technologies a company uses internally
  • GitHub and code repositories — Developers sometimes accidentally push credentials or internal URLs

A solid OSINT pass can tell you the company's email format, internal technology stack, names of IT staff, subdomains, and even software versions — all without touching their network once.

Footprinting

Footprinting is the structured process of mapping out a target's digital footprint. It feeds directly from OSINT and covers:

  • Domain and subdomain enumeration — What domains does this organization own? What subdomains are exposed?
  • IP range identification — What IP addresses does the organization control?
  • Email harvesting — What employee emails are publicly discoverable?
  • Technology fingerprinting — What web server, CMS, or cloud provider are they using?
  • Network topology mapping — What can we infer about how their infrastructure is connected?

Footprinting bridges the gap between raw data collection (OSINT) and targeted scanning.

Key Tools in This Phase

theHarvester

A straightforward but powerful tool for harvesting emails, subdomains, IPs, and URLs from public sources. It queries engines like Google, Bing, LinkedIn, and VirusTotal simultaneously.

theHarvester -d target.com -b google,linkedin

Best used early — it gives you a quick overview of an organization's publicly exposed digital assets.

Maltego

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A visual intelligence tool that maps relationships between entities — domains, emails, people, IP addresses, social media profiles, and more. It uses transforms (automated queries against data sources) to build a web of connections.

Where theHarvester gives you a list, Maltego gives you a graph. It's especially powerful for visualizing how employees, domains, and infrastructure interconnect — useful in corporate and enterprise engagements.

Shodan

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Often called "the search engine for hackers," Shodan indexes internet-connected devices — routers, webcams, industrial control systems, databases, and servers — along with their banners, ports, and service versions.

A simple Shodan search for a target's IP range can reveal:

  • Open ports and services
  • SSL certificate metadata
  • Software versions
  • Default credentials left on exposed panels
org:"Target Company Name"

This is passive recon at its most powerful — you're querying Shodan's existing crawl data, never touching the target directly.

Recon-ng

A full-featured reconnaissance framework built in Python, modeled after Metasploit's workflow. It uses modules to query different data sources — WHOIS, DNS, LinkedIn, breach databases, and more — and stores all results in a local database for structured analysis.

recon-ng
[recon-ng] > marketplace install all
[recon-ng] > workspaces create target_engagement
[recon-ng] > modules load recon/domains-hosts/hackertarget
[recon-ng] > options set SOURCE target.com
[recon-ng] > run

Recon-ng is ideal when you want a repeatable, documented recon workflow — especially useful for reporting purposes.

The MITRE ATT&CK Connection

Reconnaissance maps directly to the Reconnaissance tactic in the MITRE ATT&CK framework (TA0043). Key techniques include:

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Mapping your recon activities to ATT&CK is important for writing accurate VAPT reports — it gives clients a standardized reference point for what was done and what risks it relates to.

Recon in the Real World: The Flow

Define Scope
     ↓
Passive OSINT (Shodan, theHarvester, LinkedIn, WHOIS)
     ↓
Footprinting (subdomains, email format, IP ranges)
     ↓
Visual Mapping (Maltego)
     ↓
Structured Analysis (Recon-ng)
     ↓
Active Recon (only within approved scope)
     ↓
Feed findings into Phase 2: Scanning & Enumeration

Key Takeaways

  • Reconnaissance is the foundation — weak recon leads to incomplete testing
  • Always begin passively; only go active when authorized
  • OSINT can reveal a surprising amount about any organization's attack surface
  • Tools like theHarvester, Shodan, Maltego, and Recon-ng each serve a distinct purpose — use them together, not in isolation
  • Document everything and map it to MITRE ATT&CK for professional reporting

This is Part 1 of a VAPT lifecycle series. The next post covers scanning and enumeration — where we take the map we just built and start probing it.