Cybersecurity Technologies

Pen Testing

Penetration testing (pen testing) is a controlled, authorized attack against your systems conducted by security professionals to find exploitable vulnerabilities before real attackers do. Unlike automated scanning, pen testing involves human expertise to chain together weaknesses, test business logic, and simulate realistic attack scenarios against your applications, infrastructure, and processes.

What is penetration testing?

Penetration testing, commonly called pen testing, is a security assessment where skilled professionals attempt to exploit vulnerabilities in your systems using the same techniques real attackers employ. The goal is to find weaknesses that automated tools miss by applying human creativity, contextual understanding, and the ability to chain together multiple low-severity issues into a significant compromise.

A pen test typically follows a structured methodology:

  1. Scoping and reconnaissance. Define what's in scope (applications, networks, cloud infrastructure, APIs), gather information about the target, and identify potential entry points.
  2. Vulnerability identification. Discover security weaknesses through a combination of automated scanning and manual analysis.
  3. Exploitation. Attempt to exploit identified vulnerabilities to demonstrate real-world impact. This is where human expertise matters most: testers chain together findings, bypass controls, and test business logic in ways automated tools cannot.
  4. Post-exploitation. If initial access is gained, assess how far an attacker could go. Can they escalate privileges? Move laterally? Access sensitive data? Pivot to other systems?
  5. Reporting. Document findings with evidence, severity ratings, business impact assessments, and specific remediation guidance.

Pen tests come in several varieties: external (testing internet-facing assets), internal (simulating an insider or someone who's breached the perimeter), web application (focused on a specific app or API), social engineering (testing human vulnerabilities like phishing), and red team (a broader, adversarial simulation of a real-world attack campaign).

Why pen testing matters for startups

For startups, the question isn't whether you need pen testing, but when and how often.

Here's why it matters:

  1. Automated tools have limits. Vulnerability scanners and DAST tools are excellent at finding known vulnerability patterns, but they can't test business logic, chain together findings creatively, or think like an attacker. A pen tester might discover that combining a low-severity information disclosure with a medium-severity API flaw creates a critical data breach path that no automated tool would flag.
  2. Compliance requirements are specific. SOC 2 auditors expect evidence of regular penetration testing. PCI DSS 4.0 explicitly requires annual internal and external pen tests. Many enterprise customers require a recent pen test report as part of vendor due diligence. Having a clean pen test report accelerates procurement conversations significantly.
  3. Costs are reasonable for startups. Generally, a penetration test will run you a fraction of the cost of a breach, and the findings typically improve your security posture more than any single tool purchase.
  4. It validates your defenses. Pen testing is the only way to test whether your security controls actually work together as intended. You might have great authentication, solid input validation, and proper encryption, but a pen tester might find that the password reset flow bypasses two of those three controls. It's the difference between having security features and having effective security.

How Fencer complements pen testing

Fencer and pen testing serve different but complementary purposes. Fencer provides continuous, automated security monitoring. Pen testing provides periodic, human-driven security assessment. Together, they give you both breadth and depth.

How they work together:

  • Fencer reduces pen test scope and cost. When a pen tester arrives and your SAST, CSPM, and EASM findings are already triaged and remediated, they spend less time on low-hanging fruit and more time on complex attack chains that automated tools can't find. This means more value per dollar spent on pen testing.
  • Fencer catches issues between pen tests. Pen tests are point-in-time. Fencer runs continuously. The vulnerability introduced on Tuesday after your annual pen test doesn't go undetected until next year's test.
  • Pen test findings inform Fencer priorities. If a pen tester discovers that a specific class of vulnerability is your biggest risk, you can adjust your Fencer configuration to prioritize that category going forward.

Frequently asked questions

What is the difference between a pen test and a vulnerability scan?

A vulnerability scan is an automated process that checks your systems against a database of known vulnerabilities. It's fast, repeatable, and covers a broad surface, but it only identifies potential issues without verifying them. A penetration test is a manual, expert-driven assessment where a security professional actively tries to exploit vulnerabilities, chain them together, and demonstrate real-world impact. Vulnerability scans tell you what might be wrong. Pen tests prove what's actually exploitable and how far an attacker could get.

Toggle answer

How often should a startup get a pen test?

At minimum, once per year for compliance purposes (SOC 2, PCI DSS). Beyond that, schedule additional pen tests after major product releases, significant infrastructure changes, or before launching a new product. Many startups adopt a hybrid model: annual comprehensive pen tests supplemented by continuous automated scanning (SAST, DAST, CSPM) to catch issues between tests. As your product matures and your customer base grows, increasing to semi-annual testing is common.

Toggle answer

Should startups choose internal or external pen testing?

Start with external pen testing, which evaluates your internet-facing attack surface (web applications, APIs, cloud infrastructure). This is where most attacks originate and what compliance frameworks prioritize. Internal pen testing (simulating an insider threat or a post-breach scenario) becomes important as your team grows and your infrastructure becomes more complex. For most early-stage startups, an external web application and cloud infrastructure pen test provides the highest return on investment.

Toggle answer

Secure your startup’s momentum