Pentest

What Is a Pentest

A pentest (penetration test) is a simulated, controlled “attack” on your system with the sole purpose of finding vulnerabilities before intruders find them. Simply put, you invite “good hackers” to try to hack into your infrastructure, applications, or networks — but they do it according to the rules so as not to harm you.

Why is this necessary? Because vulnerabilities are inevitable: code changes, configurations break, and people make mistakes. Pentest is a way not to guess, but to find out the facts. Imagine that the test is a fire drill: it’s better to see how the fire alarm works and where the paint bottle lights up before anyone gets hurt.

When is the pentest held?

• Before a product release or major update — to avoid “surprises” in the product.
• After major changes in the architecture (new services, migration to the cloud).
• According to the regulations: annually, quarterly, or according to industry/audit requirements.
• After a security incident, to understand the attack vector and close the traces.

Who needs a pentest? Almost everyone: businesses with critical data (finance, medicine), SaaS platforms, banks, the public sector, and startups that want to convince investors and customers of a serious approach to security. Pentest is not a luxury, but an investment in reputation and business continuity.

Historical Background: Evolution of Pentesting

The history of pentest is actually the history of cybersecurity in general.

• 1980s and 1990s. Manual attacks.The first “hackers” tested systems without a formal structure. The first teams appeared that took money for hacking attempts (usually banking systems).
• 2000s: Standardization. Internet security has become a massive issue. OWASP, commercial scanners, and report formats have appeared. The web has become the focus of attention: SQL injection, XSS, CSRF.
• 2010s: Cloud and Mobility. The massive distribution of AWS, Azure, and Google Cloud has added a new layer. Bug bounty programs appeared: Facebook, Google and others started paying for vulnerabilities. Automation has become the norm.
• Now and the future. Pentest is integrated into DevSecOps: “Shift Left” — checking the code and environment before production. AI/ML tools are used to find vulnerability patterns and generate exploits. The role of Red and Purple teams is increasing: now it’s not only about finding holes, but also about training businesses to respond to attacks in real time.

Pentest has gone from being a “lone hacker” to an industry with methodologies, certifications, and standards embedded in the development and audit cycle.

Types of Pentesting (by scope and method)

Pentest is not a single action, but a set of scenarios. It is important to choose the right format depending on the task.

According to the tester’s information level:

• Black box is a blind test. The tester receives no internal information: no code, no architecture. This is as close as possible to a real external attack: they check only what is available from the Internet. Great for evaluating the protection of external perimeters.
• White box — full access to everything: source codes, architectural schemes, accounts. This is a deep audit, similar to an audit “under the hood”: it allows you to find hidden logical errors, configuration errors and problem areas in the code.
• Grey box — compromise: the tester has partial information (for example, an account with low rights or network diagrams). This is a realistic internal threat scenario — an employee or contractor with limited access.

By testing objects:

• Network pentest — checking the network perimeter, firewalls, services, and open ports.
• Web app pentest — testing of web applications: injections, XSS, authorization logic, data leaks.
• Mobile pentest — applications for iOS/Android: local data storage, insecure APIs, key protection.
• API pentest — checking REST/GraphQL/WebSocket interfaces: authorization, rate-limit, leaks.
• Cloud pentest — security of cloud configurations, IAM policies, S3 buckets, and network rules.
• IoT pentest — devices, firmware, communication protocols, physical security.

Red team vs Blue team vs Purple team:

• Red team is an attacking team acting as a target threat (broad, real scenario).
• Blue team — internal defense: monitoring, response, protection measures.
• Purple team — Red and Blue collaboration: the goal is not just to show problems, but also to work out protection and processes quickly and efficiently.

Each type has its own goal and scale: a well-chosen scenario gives the most useful result without unnecessary risk.

Pentest Methodology: Phases and What to Expect

A professional pentest is not a brick theft at night, but a structured process with stages, clear rules and accountability. Expect the following phases:

1. Reconnaissance (recon) — information collection. This is intelligence: domains, subdomains, public WHOIS, IP ranges, open ports, service versions, and public configuration leaks are collected. They use OSINT tools, passive scanning is the goal to understand the “attack surface”. Example: an old subdomain is found dev.example.com with a forgotten web interface, vulnerabilities are often hidden there.
2. Scanning & Numbering — deep mapping. Here they use Nmap, vulnerability scanners, search for paths on the web, identify components (NGINX, Apache, PHP versions), and check open admin interfaces. This is a map of the area before the attacks. Important: at this stage, they record the “what’s where” and determine the priorities for exploitation.
3. Exploitation — attempts to exploit vulnerabilities. The tester is trying to “crack” the weaknesses found: SQL injection, RCE, authentication bypass. Everything is done in a controlled manner: the goal is to show the risk, not destroy the system. PoC (proof-of-concept) is often used, which is a reproducible integrated example of an attack. Ethics are important: exploiting is limited to the limits stipulated in the RoE (rules of engagement).
4. Post-exploitation / Persistence — what can be done after hacking. If the tester has gained access, he checks whether it is possible to raise privileges, save access, replace data, or navigate the network. This stage demonstrates the real danger: obtaining credit data, reading internal documents, or obtaining administrator credentials.
5. Reporting & Remediation — report and correction. Key stage: a detailed report with priorities (Critical/High/Medium/Low), playback steps (PoC), screenshots/logs, and specific fix recommendations. The report should be clear to both the technical team and management: “what to fix first” and “what will lead to immediate risks.” After fixes, a retest is often carried out to make sure that the vulnerabilities are really closed.
6. Rules of Engagement — rules of the game. Before the start, the following is agreed upon: test objects, acceptable times, emergency contacts, acceptable methods, notification procedures, and escalation. This is a mandatory part — without RoE, the pentest becomes a business risk.

Tools and Platforms Commonly Used in Pentesting

Pentest without instruments is like surgery without a scalpel: you can try, but the result will be questionable. The industry has developed a whole arsenal of software and frameworks that have become the standard.

• Scanners and frameworks.
  • Nmap is a basic intelligence tool: from “which ports are open” to scripts to identify vulnerabilities.
  • Nessus and OpenVAS are industrial vulnerability scanners that check thousands of known CVEs and provide a ready—made report.
  • Nikto is an old—school web scanner that searches for unsafe CGI scripts, configuration files, and server errors.
• Web Application Tools.
  • Burp Suite is the gold standard of web pentest: interception and modification of requests, fuzzing, integration with plugins.
  • OWASP ZAP is a free alternative to Burp, convenient for starting and automating in CI/CD.
• Exploit Frameworks.
  • Metasploit is a huge library of exploits, plus a framework for creating your own.
  • SQLmap is an automated tool for SQL injection.
  • Mimikatz is a legendary tool for working with Windows loans, especially in domain networks.
• Cloud & Container Tools.
  • ScoutSuite, Prowler — audit AWS, GCP, Azure for incorrect configurations.
  • kube-bench — checking Kubernetes clusters for compliance with security standards.
• Scripts and automation.
  • Python, Bash, and PowerShell are the workhorses. Pentesters often write their own utilities for a specific project, and companies implement CI/CD scanners directly into the pipeline.
• Sandboxes and test environments. From virtual machines running Kali Linux to specialized “mazes” (HackTheBox, VulnHub). These are platforms for testing exploits without the risk of harming combat systems.

The tools are just the hands of a craftsman. The main thing is methodology and the ability to correctly interpret the conclusion.

Legal, Ethical and Organizational Considerations

Pentest is not about “playing cracker”. This is a process where legality and ethics are worth no less than technical skills.

• Legality. Any pentest starts with a piece of paper: a contract, an SLA, and most importantly, Authorization to Test. Without this, any check can be considered an attack, with criminal consequences.
• Ethics. The golden rule is: do no harm. A tester should not break data, publish privacy, or interfere with business. Everything is done transparently: there are borders, contacts and emergency communication channels.
• Documents and processes.
  • SOW (Statement of Work) — what exactly is being tested.
  • Rules of Engagement (RoE) — how we test which methods are allowed.
  • Incident plan — what do we do if the test is accidentally dropped by the prod.
• Internal risks. Pentest is a load: from dropping services to leaks in logs. Therefore, backups, emergency plans, and recovery SLAs are prepared in advance.
• Choosing a provider. They look at certifications (OSCP, AXIS, CREST), real-world cases, and what their reporting looks like. A real pro will not only find holes, but also help close them.

Pentest can be also seen as a tool agains DDoS attacks and if you want to know hot to protect against DDoS feel free to check our article on it.

This part is often more boring for engineers, but without it, any pentest turns into chaos.