What is Pentesting? Complete Penetration Testing Guide, Process & Tools 2026

Penetration testing (pentesting) is one of the most effective ways to identify security vulnerabilities before malicious actors exploit them. By simulating real-world cyberattacks using the same tools and techniques as criminals, ethical hackers uncover weaknesses in your defenses, validate security controls, and provide actionable recommendations for strengthening your security posture. This comprehensive guide explains what pentesting is, different testing types and methodologies, the penetration testing process, essential tools used by professionals, certification paths, pricing considerations, and best practices, helping you understand how penetration testing fits into your overall security strategy.

What is Pentesting (Penetration Testing)?

Pentesting, short for penetration testing or ethical hacking, is an authorized simulated cyberattack performed by security professionals to identify and exploit vulnerabilities in systems, networks, applications, and security controls. Pentesters (white hat hackers) use real-world attack techniques, but with explicit permission and ethical boundaries, to discover security weaknesses that could be exploited by malicious actors.

Unlike automated vulnerability scanning that simply identifies potential weaknesses, pentesting validates whether vulnerabilities are actually exploitable, determines the impact of successful exploitation, tests the effectiveness of security controls and detection capabilities, and demonstrates real-world attack scenarios to stakeholders, providing organizations with concrete evidence of security gaps and prioritized remediation guidance.

Types of Penetration Testing

1. Network Penetration Testing

Testing network infrastructure security:

• External pentest: Attacks from internet-facing perspective
• Internal pentest: Simulating insider or lateral movement after breach
• Targets: Firewalls, routers, switches, VPNs, wireless networks
• Objectives: Unauthorized access, data exfiltration, network segmentation bypass
• Common findings: Open ports, weak passwords, misconfigured firewalls, unpatched systems

2. Web Application Penetration Testing

Testing web application security:

• Testing for: SQL injection, cross-site scripting (XSS), authentication bypass
• Also testing: Session management, authorization flaws, API security
• Targets: Customer portals, e-commerce sites, SaaS applications, APIs
• Methodology: OWASP Testing Guide and Top 10
• Tools: Burp Suite, OWASP ZAP, Nikto

3. Mobile Application Pentesting

Testing mobile app security:

• iOS and Android: Platform-specific vulnerabilities
• Testing areas: Data storage, cryptography, authentication, API communication
• Common issues: Insecure data storage, weak encryption, certificate pinning bypass
• Framework: OWASP Mobile Security Testing Guide

4. Cloud Penetration Testing

Testing cloud infrastructure and services:

• Platforms: AWS, Azure, Google Cloud security
• Focus areas: IAM misconfigurations, storage buckets, API security, container security
• Challenges: Requires provider permission and compliance with terms of service
• Tools: ScoutSuite, Prowler, Pacu

5. Wireless Network Pentesting

Testing WiFi and wireless security:

• Testing: WPA2/WPA3 encryption strength, rogue access points, guest network isolation
• Attacks: Password cracking, evil twin attacks, man-in-the-middle
• Tools: Aircrack-ng, Kismet, WiFi Pineapple

6. Social Engineering Testing

Testing human element security:

• Phishing campaigns: Simulated phishing emails testing user awareness
• Vishing: Phone-based social engineering
• Physical security: Unauthorized facility access attempts
• Objective: Measure user susceptibility and improve training

Pentesting Methodologies

Testing Approaches

Black Box Testing

• Knowledge level: No information provided to tester
• Simulates: External attacker with no inside knowledge
• Advantages: Most realistic external threat simulation
• Disadvantages: Time-consuming, may miss internal vulnerabilities

White Box Testing

• Knowledge level: Full information, network diagrams, credentials, source code
• Simulates: Insider threat or comprehensive assessment
• Advantages: Thorough, efficient, finds more vulnerabilities
• Disadvantages: Less realistic of external threat

Gray Box Testing

• Knowledge level: Partial information, basic credentials, network access
• Simulates: Compromised user or contractor access
• Advantages: Balance of realism and thoroughness
• Most common: Preferred by most organizations

The Penetration Testing Process

Phase 1: Planning and Reconnaissance

Duration: 1-3 days

• Scope definition: Systems, networks, applications in scope
• Rules of engagement: Testing boundaries, restricted actions, communication protocols
• Information gathering: OSINT, DNS enumeration, WHOIS lookups, public data
• Attack surface mapping: Identifying all potential entry points

Phase 2: Scanning and Enumeration

Duration: 2-5 days

• Port scanning: Discovering open ports and services (Nmap)
• Service enumeration: Identifying service versions and configurations
• Vulnerability scanning: Automated vulnerability detection
• Web application mapping: Discovering application structure and functionality

Phase 3: Exploitation

Duration: 3-10 days

• Vulnerability exploitation: Attempting to exploit identified weaknesses
• Privilege escalation: Gaining elevated permissions
• Lateral movement: Moving across network to additional systems
• Data access: Attempting to access sensitive information
• Persistence: Establishing continued access (in scope)

Phase 4: Post-Exploitation

Duration: 2-5 days

• Impact assessment: Determining scope of potential compromise
• Data exfiltration simulation: Testing ability to steal data
• Maintaining access: Testing detection evasion
• Pivoting: Using compromised systems to attack others

Phase 5: Reporting

Duration: 3-5 days

• Executive summary: High-level findings for leadership
• Technical details: Vulnerability descriptions, exploitation steps, evidence
• Risk ratings: CVSS scores and business impact assessment
• Remediation recommendations: Specific fixes prioritized by risk
• Presentation: Findings walkthrough with technical team

Phase 6: Re-Testing (Optional)

Duration: 2-5 days

• Validate that vulnerabilities are properly fixed
• Ensure remediation doesn't introduce new issues
• Provide final attestation for compliance

Essential Pentesting Tools

Reconnaissance and Scanning

• Nmap: Network discovery and port scanning
• Masscan: Fast large-scale port scanning
• Nessus/OpenVAS: Vulnerability scanning
• Shodan: Internet-connected device discovery
• theHarvester: Email and subdomain gathering

Exploitation Frameworks

• Metasploit: Comprehensive exploitation framework
• Cobalt Strike: Advanced threat emulation (commercial)
• Empire/Covenant: PowerShell post-exploitation
• BeEF: Browser exploitation framework

Web Application Testing

• Burp Suite Professional: Comprehensive web app security testing
• OWASP ZAP: Open-source web app scanner
• SQLmap: Automated SQL injection detection and exploitation
• Nikto: Web server vulnerability scanner
• Wfuzz: Web application fuzzer

Password Cracking

• Hashcat: Advanced password recovery
• John the Ripper: Password cracking
• Hydra: Network login brute forcing
• Mimikatz: Credential extraction from Windows

Wireless Testing

• Aircrack-ng: WiFi security auditing suite
• Kismet: Wireless network detector
• Wifite: Automated wireless attack tool

Penetration Testing Pricing

Typical Cost Ranges

Network Penetration Tests

• Small business (1-10 IPs): $5,000-$10,000
• Mid-size (10-50 IPs): $10,000-$25,000
• Enterprise (50+ IPs): $25,000-$75,000+

Web Application Pentests

• Simple application (5-10 pages): $5,000-$10,000
• Moderate complexity (10-25 pages): $10,000-$20,000
• Complex application (25+ pages, APIs): $20,000-$50,000+

Comprehensive Organizational Assessments

• Small organization: $15,000-$35,000
• Mid-market: $35,000-$75,000
• Enterprise: $75,000-$200,000+

Pricing Factors

• Scope: Number of systems, applications, IP ranges
• Duration: Testing days required (typically 5-20 days)
• Depth: Thoroughness level, quick assessment vs comprehensive
• Complexity: Modern vs legacy systems, custom applications
• Tester expertise: Junior vs senior vs specialized experts
• Compliance requirements: PCI DSS pentests require qualified assessors
• Re-testing: Validation testing after remediation (typically 30-50% of initial cost)

Pentesting vs Vulnerability Assessment

Aspect	Vulnerability Assessment	Penetration Testing
Objective	Identify potential vulnerabilities	Exploit vulnerabilities, demonstrate impact
Methodology	Automated scanning	Manual exploitation + automated tools
Depth	Comprehensive breadth	Deep exploitation of specific vulnerabilities
Risk	Low, read-only scanning	Higher, actual exploitation attempts
Duration	Hours to days	Days to weeks
Frequency	Monthly or continuous	Quarterly or annual
Output	List of potential vulnerabilities	Validated exploits, impact assessment, remediation priority
Cost	$1,000-$5,000	$5,000-$100,000+

Best practice: Use vulnerability assessments for continuous monitoring and pentesting for deep validation, they complement each other rather than replacing one another.

Penetration Testing Certifications

Industry-Recognized Certifications

• OSCP (Offensive Security Certified Professional): Hands-on practical pentesting, highly respected
• CEH (Certified Ethical Hacker): Broad ethical hacking knowledge
• GPEN (GIAC Penetration Tester): Technical pentesting skills
• GWAPT (GIAC Web Application Penetration Tester): Web app security specialization
• eCPPT (eLearnSecurity Certified Professional Penetration Tester): Practical network pentesting
• PNPT (Practical Network Penetration Tester): Real-world focused certification

When to Conduct Pentesting

Regular Schedule

• Annual minimum: At least once per year for all organizations
• Quarterly: High-risk environments, financial services, healthcare
• Compliance-driven: PCI DSS requires annual + after significant changes

Trigger Events

• New application deployment: Before production launch
• Infrastructure changes: Major network or system upgrades
• After security incidents: Validate remediation effectiveness
• Mergers and acquisitions: Before integration
• Compliance audits: As required by regulations

Frequently Asked Questions

What is pentesting?

Pentesting (penetration testing) is an authorized simulated cyberattack performed by ethical hackers to identify security vulnerabilities in systems, networks, and applications before malicious actors exploit them. Pentesters use the same tools, techniques, and methodologies as real attackers, including enumeration, exploitation, and privilege escalation, but with explicit permission and ethical boundaries. Pentesting validates whether vulnerabilities are exploitable, tests security control effectiveness, demonstrates real-world attack impact, and provides actionable remediation recommendations. It's critical for compliance (PCI DSS, HIPAA), security validation, and risk management.

What are the types of penetration testing?

Main penetration testing types include: Network pentesting (external and internal infrastructure security), Web application pentesting (testing for SQL injection, XSS, authentication flaws using tools like Burp Suite), Mobile application pentesting (iOS/Android app security), Cloud pentesting (AWS, Azure, GCP security testing), Wireless pentesting (WiFi and wireless network security), Social engineering testing (phishing simulations, physical security), and API pentesting (REST/GraphQL security). Organizations also choose between black box (no knowledge), gray box (partial knowledge), or white box (full knowledge) testing approaches based on objectives and compliance requirements.

How much does penetration testing cost?

Penetration testing costs vary widely based on scope and complexity. Small business network pentest costs $5,000-$15,000, mid-size organization comprehensive test costs $15,000-$35,000, enterprise-level pentests cost $35,000-$100,000+, web application pentests cost $5,000-$30,000 depending on complexity, cloud environment pentests cost $10,000-$50,000, and social engineering campaigns cost $3,000-$15,000. Pricing factors include scope (number of systems), testing depth and duration (typically 5-20 days), tester expertise and certifications, compliance requirements (PCI DSS pentesters cost premium), and re-testing needs. Annual pentesting is recommended minimum, with quarterly testing for high-risk environments.

How long does penetration testing take?

Penetration testing duration depends on scope and complexity. Small network pentest takes 1-2 weeks, comprehensive organizational pentest takes 2-4 weeks, web application pentest takes 1-3 weeks, cloud environment pentest takes 2-4 weeks, and large enterprise assessments take 4-8+ weeks. Timeline includes scoping and planning (1-3 days), active testing including reconnaissance, scanning, and exploitation (5-20 days), report writing (3-5 days), remediation guidance and presentation (1-2 days), and optional re-testing after fixes are implemented (2-5 days). Rush projects available but may compromise thoroughness and may miss vulnerabilities.

Conclusion: Pentesting as Proactive Defense

Pentesting provides organizations with invaluable visibility into real-world security weaknesses from an attacker's perspective. By proactively identifying and remediating vulnerabilities before criminals exploit them, pentesting reduces breach risk, validates security investments, meets compliance requirements, and demonstrates concrete security posture to stakeholders and customers.

The key to effective pentesting is treating it as an ongoing program rather than one-time checkbox exercise, conducting regular tests, remediating findings promptly, re-testing to validate fixes, and continuously improving defenses based on results. Organizations should combine pentesting with continuous vulnerability assessments, SOC monitoring, and threat intelligence for comprehensive security validation.

subrosa provides comprehensive penetration testing services including network, web application, cloud, and social engineering assessments conducted by certified ethical hackers. Our testing methodology aligns with OWASP, PTES, and compliance frameworks, delivering actionable findings with prioritized remediation guidance. We also offer red team exercises for advanced threat simulation. Contact us to schedule your next penetration test.