What is Pentesting? How Does It Work Step-by-Step?

Pentesting, or penetration testing, is a critical cybersecurity practice where testers, also known as ethical hackers, simulate cyberattacks to identify and exploit vulnerabilities in a system. The primary goal of pentesting is to find security weaknesses before malicious hackers can exploit them, thus preventing potential security breaches. This process involves a systematic approach to assess the security of information systems by mimicking the actions of potential attackers.

Understanding Pentesting

Step-by-Step Guide to the Pentesting Process

Step 1: Planning and Reconnaissance

• Objective Setting: Define what needs to be tested and the goals of the penetration test. This could include determining the systems, networks, or applications that will be the focus of the test.
• Information Gathering: Collect information to understand how the target system operates and its potential vulnerabilities. This phase involves gathering public data that could include domain names, server IP addresses, and network infrastructure details.

Step 2: Scanning

• Static Analysis: Inspect the code without executing it to find vulnerabilities.
• Dynamic Analysis: Assess the code during execution. This often involves using automated tools to scan for vulnerabilities that can be exploited.
• Vulnerability Scanning: Use tools to automate the discovery of security weaknesses, such as outdated software, misconfigurations, and susceptibilities to injection attacks.

Step 3: Gaining Access

• Exploitation: Use the vulnerabilities found during the scanning phase to try and exploit the system. This could involve escalating privileges, intercepting traffic, or stealing data.
• Exploit Scripts: Utilize pre-written or custom scripts to automate the exploitation of vulnerabilities.

Step 4: Maintaining Access

• Persistence: The tester tries to create a persistent presence on the exploited system, simulating what an attacker might do to maintain access long enough to achieve a deep presence for deeper data theft or system harm.
• Simulated Advanced Threats: Emulate advanced persistent threats to see how well the system can handle skilled, long-term intruders.

Step 5: Analysis and WAF Configuration

• Data Collection: Gather data from the testing process, documenting the vulnerabilities exploited, the data accessed, and the length of time the tester was able to remain in the system undetected.
• Security Report: Compile a detailed report that includes the vulnerabilities discovered, the data that was accessed, how long the tester was able to maintain access, and recommendations for securing the system.
• Feedback Session: Discuss the findings with the client, providing a comprehensive review of security weaknesses and recommendations for improvement.

Step 6: Remediation

• Patch Management: Address the specific vulnerabilities found during the pentest by applying patches or making system configuration changes.
• Re-testing: After fixes are made, re-testing certain aspects of the system to ensure vulnerabilities are adequately addressed.

Tools Used in Pentesting

Network Scanning Tools:

• Nmap (Network Mapper): Used for network discovery and security auditing, Nmap is invaluable for finding devices on a network, identifying open ports, and detecting security risks.
• Wireshark: A network protocol analyzer that lets users capture and interactively browse the traffic running on a computer network.
• Masscan: Known as the fastest Internet port scanner, it can scan the entire Internet in under six minutes, transmitting 10 million packets per second.

Vulnerability Scanners

• Nessus: Highly popular in vulnerability scanning, Nessus detects vulnerabilities that malicious actors could use to penetrate a network.
• OpenVAS: A full-featured vulnerability scanner that is widely used for high-speed discovery of vulnerabilities.
• Qualys Guard: A cloud-based scanner that provides automated scanning of vulnerabilities and integrates with a suite of other security tools for comprehensive testing.

Web Application Testing Tools

• Burp Suite: An integrated platform aimed at performing security testing of web applications, it offers a variety of tools with powerful features.
• OWASP ZAP (Zed Attack Proxy): An easy-to-use integrated penetration testing tool for finding vulnerabilities in web applications.
• SQLmap: An open source penetration testing tool that automates the process of detecting and exploiting SQL injection flaws and taking over database servers.

Wireless Testing Tools

• Aircrack-ng: A complete suite of tools to assess WiFi network security focusing on different areas of WiFi security like monitoring, attacking, testing, and cracking.
• Kismet: A network detector, packet sniffer, and intrusion detection system for 802.11 wireless LANs.

Exploitation Frameworks

• Metasploit Framework: Allows the development and execution of exploit code against a remote target machine. It also acts as a resource for those who need to validate and improve their defensive strategies.
• BeEF (Browser Exploitation Framework): A powerful professional tool that leverages web browsers as pivot points to initiate broader security assessments.

Password Cracking Tools

• John the Ripper: Well-known among password cracking tools, it automatically detects password hash types and includes a customizable cracker.
• Hashcat: Claimed to be the world’s fastest CPU-based password recovery tool, it is highly versatile and supports many algorithms.

Configuration and Compliance Analysis

• Chef InSpec: Automates configuration testing, ensuring compliance against security requirements and standards.
• Lynis: A security auditing tool for Unix-based systems, it performs extensive health scans of systems to support system hardening and compliance testing.

Forensic Tools

• Autopsy and The Sleuth Kit: Helps in recovering evidence from digital data, often used in law enforcement to solve crimes but also valuable for detecting how a breach occurred.

Reverse Engineering Tools

• IDA Pro: A disassembler and debugger that is popular for reverse engineering, allowing analysts to see how a program works or what a malicious code would do.

Reporting in Pentesting

1. Executive Summary: Provides an overview of the pentest results, highlighting key vulnerabilities and the potential impact on the organization.

2. Detailed Findings: Each vulnerability is reported with a detailed description, evidence (screenshots/code snippets), and an explanation of potential consequences.

3. Risk Assessment: Vulnerabilities are categorized by risk level (high, medium, low) based on factors such as exploitability and potential damage.

4. Remediation Strategies: Specific, actionable advice on how to fix the vulnerabilities.

5. Re-Test Offer: An offer to re-test the systems after fixes are applied to ensure that the solutions were effective and no new vulnerabilities were introduced.

Pentesting is an indispensable component of an organization’s cybersecurity strategy. By understanding and implementing a thorough pentesting process, organizations can enhance their defenses against real-world cyber threats. Regular penetration testing helps maintain a robust security posture by continually identifying and addressing vulnerabilities.