{"id":10668,"date":"2026-06-27T21:27:14","date_gmt":"2026-06-27T21:27:14","guid":{"rendered":"https:\/\/garrisonone.com\/blog\/?p=10668"},"modified":"2026-06-27T21:27:15","modified_gmt":"2026-06-27T21:27:15","slug":"what-is-penetration-testing","status":"publish","type":"post","link":"https:\/\/garrisonone.com\/blog\/what-is-penetration-testing\/","title":{"rendered":"What Is Penetration Testing? A Plain-English Guide"},"content":{"rendered":"\n<style>\n.go-callout{display:block!important;background:#f0f4ff!important;border-left:4px solid #1a3faa!important;padding:14px 18px!important;margin:24px 5%!important;border-radius:0 4px 4px 0!important;font-size:1em!important;line-height:1.6!important;}\n.go-cta{background:#0d1f5c!important;color:#fff!important;padding:32px!important;border-radius:8px!important;margin:40px 5%!important;text-align:center!important;}\n.go-cta h3,.go-cta-heading{color:#fff!important;margin-top:0!important;font-size:22px!important;}\n.go-cta p{color:#fff!important;font-size:16px!important;}\n.go-cta-btn{display:inline-block!important;background:#fff!important;color:#0d1f5c!important;padding:10px 24px!important;border-radius:4px!important;font-weight:bold!important;text-decoration:none!important;margin-top:12px!important;font-size:16px!important;}\n.go-table{border-collapse:collapse!important;margin:32px 5%!important;font-size:16px!important;width:90%!important;}\n.go-table thead tr{background:#0d1f5c!important;}\n.go-table thead th{padding:12px 18px!important;text-align:left!important;font-weight:600!important;color:#fff!important;font-size:15px!important;}\n.go-table tbody tr{background:#fff!important;}\n.go-table tbody tr:hover{background:#f8f9ff!important;}\n.go-table td{padding:12px 18px!important;vertical-align:middle!important;border-bottom:1px solid #e0e6f0!important;font-size:15px!important;color:#222!important;}\n.go-table td:first-child a{color:#1a3faa!important;font-weight:600!important;}\n.go-img{width:100%!important;height:auto!important;margin:32px 0!important;display:block!important;}\n<\/style>\n\n<img decoding=\"async\" src=\"https:\/\/garrisonone.com\/assets\/svg_blog\/hero-pentest.svg\" alt=\"What is penetration testing \u2014 garrisonOne\" class=\"go-img\" \/>\n\n<p>Every business has security weaknesses. The question is whether you find them first \u2014 or an attacker does.<\/p>\n\n<p>Penetration testing (also called pen testing or ethical hacking) is how you find out. A security professional \u2014 one you authorise and hire \u2014 attempts to break into your systems using the same techniques a real attacker would use. The difference: they hand you a detailed report instead of stealing your data.<\/p>\n\n<p>This guide explains exactly what penetration testing is, how it works, the types available, and whether your business actually needs it.<\/p>\n\n<div class=\"go-callout\"><strong>Quick answer:<\/strong> Penetration testing is a controlled, authorised cyberattack on your own systems \u2014 designed to find vulnerabilities before real attackers do.<\/div>\n\n<img decoding=\"async\" src=\"https:\/\/garrisonone.com\/assets\/svg_blog\/post01-pentest-vs-attacker.svg\" alt=\"Penetration tester vs real attacker comparison\" class=\"go-img\" \/>\n\n<h2>What does a pen tester actually do?<\/h2>\n\n<p>A penetration tester uses the same tools, tactics, and techniques as a malicious hacker \u2014 but with your knowledge and permission. During a test, they might:<\/p>\n\n<ul>\n<li>Try to access systems using stolen, guessed, or phished credentials<\/li>\n<li>Exploit known vulnerabilities in your software or web applications<\/li>\n<li>Attempt to intercept unencrypted network traffic<\/li>\n<li>Send phishing emails to your employees to test awareness<\/li>\n<li>Look for misconfigurations in cloud environments, firewalls, or servers<\/li>\n<li>Try to escalate privileges after gaining initial access<\/li>\n<\/ul>\n\n<p>The goal isn&#8217;t just to find a weakness &#8212; it&#8217;s to exploit it the same way a real attacker would. That&#8217;s what makes a pen test different from a basic <a href=\"\/penetration-testing\/vulnerability-assessment\">vulnerability assessment<\/a>, which only identifies potential issues without testing whether they can actually be used.<\/p>\n\n<h2>Why do businesses need penetration testing?<\/h2>\n\n<p>Three reasons drive most businesses to book a pen test:<\/p>\n\n<h3>1. Compliance requirements<\/h3>\n<p>Many regulatory frameworks &#8212; including <a href=\"\/compliance\/pci-dss-compliance\"><strong>PCI DSS<\/strong><\/a>, <a href=\"\/compliance\/iso-27001-compliance\"><strong>ISO 27001<\/strong><\/a>, <a href=\"\/compliance\/soc-2-compliance\"><strong>SOC 2<\/strong><\/a>, and <a href=\"\/compliance\/hipaa-compliance\"><strong>HIPAA<\/strong><\/a> &#8212; either require or strongly recommend regular penetration testing. If you process card payments or handle sensitive data, you may not have a choice.<\/p>\n\n<h3>2. Proactive risk reduction<\/h3>\n<p>The average cost of a data breach in 2024 was $4.88 million (IBM Cost of a Data Breach Report). A pen test typically costs a fraction of that &#8212; and finding a critical vulnerability before attackers do can prevent a breach entirely.<\/p>\n\n<h3>3. Proving security to customers and partners<\/h3>\n<p>Enterprise buyers increasingly require vendors to demonstrate security assurance before signing contracts. A recent pen test report &#8212; especially from an independent third party &#8212; is one of the fastest ways to satisfy that requirement.<\/p>\n\n<h2>How penetration testing works: the 5 phases<\/h2>\n\n<p>Every professional pen test follows a structured methodology. Here&#8217;s what happens at each stage:<\/p>\n\n<img decoding=\"async\" src=\"https:\/\/garrisonone.com\/assets\/svg_blog\/post01-pentest-5phases.svg\" alt=\"5 phases of penetration testing: Planning, Recon, Scanning, Exploitation, Reporting\" class=\"go-img\" \/>\n\n<h3>Phase 1 &#8212; Planning<\/h3>\n<p>Before anything begins, you and the pen testing provider agree on scope: which systems are in scope, what testing methods are permitted, testing windows (to avoid disrupting production), and rules of engagement. Everything is documented and signed off.<\/p>\n\n<h3>Phase 2 &#8212; Reconnaissance<\/h3>\n<p>The tester gathers information about your environment &#8212; domain names, IP addresses, employee names, technologies used, publicly exposed services. This mirrors exactly what an attacker would do before launching an attack.<\/p>\n\n<h3>Phase 3 &#8212; Scanning<\/h3>\n<p>Using specialised tools, the tester maps your network: open ports, running services, software versions, and known vulnerabilities. This builds a picture of potential entry points.<\/p>\n\n<h3>Phase 4 &#8212; Exploitation<\/h3>\n<p>This is the active testing phase. The tester attempts to exploit the vulnerabilities identified &#8212; trying to gain access, escalate privileges, move laterally across the network, and reach sensitive data. All activity is logged.<\/p>\n\n<h3>Phase 5 &#8212; Reporting<\/h3>\n<p>You receive a detailed report covering every vulnerability found, evidence of exploitation, risk ratings, and specific remediation recommendations. Most providers also offer a debrief call to walk through findings.<\/p>\n\n<h2>Types of penetration testing<\/h2>\n\n<p>Not all pen tests are the same. The right type depends on what you&#8217;re trying to protect:<\/p>\n\n<img decoding=\"async\" src=\"https:\/\/garrisonone.com\/assets\/svg_blog\/post01-pentest-types.svg\" alt=\"Four types of penetration testing: Network, Web App, Social Engineering, Cloud\" class=\"go-img\" \/>\n\n<table class=\"go-table\">\n<thead>\n<tr>\n<th>Type<\/th>\n<th>What it tests<\/th>\n<th>Typical duration<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><a href=\"\/penetration-testing\/network-penetration-testing\">Network pen test<\/a><\/td>\n<td>Firewalls, routers, internal network<\/td>\n<td>3&#8211;5 days<\/td>\n<\/tr>\n<tr>\n<td><a href=\"\/penetration-testing\/web-application-penetration-testing\">Web application test<\/a><\/td>\n<td>Websites, portals, APIs<\/td>\n<td>3&#8211;7 days<\/td>\n<\/tr>\n<tr>\n<td><a href=\"\/penetration-testing\/social-engineering-testing\">Social engineering<\/a><\/td>\n<td>Employee susceptibility to phishing<\/td>\n<td>1&#8211;2 weeks<\/td>\n<\/tr>\n<tr>\n<td><a href=\"\/cloud-security\">Cloud security test<\/a><\/td>\n<td>AWS \/ Azure \/ GCP configuration<\/td>\n<td>3&#8211;5 days<\/td>\n<\/tr>\n<tr>\n<td><a href=\"\/penetration-testing\/red-team-services\">Red team exercise<\/a><\/td>\n<td>Full attack simulation across all vectors<\/td>\n<td>2&#8211;4 weeks<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n<h2>What happens after a pen test?<\/h2>\n\n<p>A good pen testing provider doesn&#8217;t just hand you a list of vulnerabilities and disappear. After the test, you should receive:<\/p>\n\n<ul>\n<li><strong>An executive summary<\/strong> &#8212; a non-technical overview of risk for leadership and board-level stakeholders<\/li>\n<li><strong>A technical findings report<\/strong> &#8212; full details of every vulnerability, how it was exploited, and evidence<\/li>\n<li><strong>Risk ratings<\/strong> &#8212; critical, high, medium, low, and informational findings prioritised by impact<\/li>\n<li><strong>Remediation guidance<\/strong> &#8212; specific steps to fix each issue, not just a list of problems<\/li>\n<li><strong>A debrief call<\/strong> &#8212; a walkthrough of findings with your technical team<\/li>\n<\/ul>\n\n<p>Once your team has remediated the critical and high findings, many providers offer a re-test to verify the fixes worked.<\/p>\n\n<h2>How often should your business do a pen test?<\/h2>\n\n<ul>\n<li><strong>Annually as a minimum<\/strong> &#8212; for most businesses, one comprehensive test per year is the baseline<\/li>\n<li><strong>After major changes<\/strong> &#8212; a new product launch, cloud migration, or acquisition warrants a targeted test<\/li>\n<li><strong>Before compliance audits<\/strong> &#8212; PCI DSS requires annual pen testing; booking one ahead of your audit gives you time to remediate findings<\/li>\n<li><strong>Quarterly for high-risk environments<\/strong> &#8212; financial services and healthcare organisations often test more frequently<\/li>\n<\/ul>\n\n<h2>Penetration testing vs vulnerability scanning: what&#8217;s the difference?<\/h2>\n\n<p>A <strong>vulnerability scan<\/strong> is automated software that checks your systems against a database of known vulnerabilities. It&#8217;s fast, relatively cheap, and useful &#8212; but it only identifies potential weaknesses without attempting to exploit them.<\/p>\n\n<p>A <strong>penetration test<\/strong> is manual, expert-led, and goes further. A tester doesn&#8217;t just flag that a vulnerability exists &#8212; they prove it can be exploited, show what data or access could be reached, and demonstrate the business impact.<\/p>\n\n<p>Think of a vulnerability scan as a checklist and a penetration test as a live fire exercise. See our <a href=\"\/penetration-testing\/vulnerability-assessment\">vulnerability assessment service<\/a> for more on how the two work together.<\/p>\n\n<div class=\"go-callout\"><strong>See it in practice:<\/strong> Read how we helped an <a href=\"\/casestudy\/ecommerce-pentest\">e-commerce retailer uncover critical vulnerabilities<\/a> before their peak trading season &#8212; and what was found.<\/div>\n\n<p>If you operate in a regulated industry, penetration testing requirements may be even more specific. See our guides for <a href=\"\/industry\/financial-services-cybersecurity\">financial services cybersecurity<\/a> and <a href=\"\/industry\/healthcare-cybersecurity\">healthcare cybersecurity<\/a> for industry-specific context.<\/p>\n\n<h2>Frequently asked questions<\/h2>\n\n<h3>Will a pen test take down our systems?<\/h3>\n<p>A professional pen test should not cause downtime. Before testing begins, scope and rules of engagement are agreed &#8212; including which systems are off-limits and acceptable testing windows. Most tests are conducted outside business hours to further reduce risk. That said, you should always have a backup and know your incident response contacts before any test.<\/p>\n\n<h3>How much does penetration testing cost?<\/h3>\n<p>A typical network or web application pen test runs between $5,000 and $30,000 depending on scope, environment size, and depth of testing. Red team exercises are more involved and can run higher. See our <a href=\"\/how-much-does-penetration-testing-cost\">pen testing cost guide<\/a> for a full breakdown.<\/p>\n\n<h3>Do small businesses need penetration testing?<\/h3>\n<p>Yes &#8212; and attackers agree. Small businesses are increasingly targeted precisely because they tend to have fewer security controls. If you handle customer data, process payments, or provide services to larger organisations, a pen test is worth considering. Many SMB-focused tests are scoped to keep costs manageable.<\/p>\n\n<h3>What&#8217;s the difference between a pen test and a red team exercise?<\/h3>\n<p>A penetration test targets specific systems or applications within a defined scope. A <a href=\"\/penetration-testing\/red-team-services\">red team exercise<\/a> is a broader, scenario-based simulation of a full attack &#8212; covering network, physical access, and social engineering in combination &#8212; with no pre-defined scope. Red team engagements are longer, more expensive, and better suited to organisations with a mature security posture already in place.<\/p>\n\n<h3>How do we prepare for a pen test?<\/h3>\n<p>You don&#8217;t need to clean up your environment first &#8212; that defeats the purpose. What you should do: make sure your team knows the test is happening, have a contact list ready in case something unexpected is discovered, and ensure your test provider has signed an NDA and rules of engagement before work begins.<\/p>\n\n<div class=\"go-cta\">\n<h3 class=\"go-cta-heading\">Ready to find your vulnerabilities before attackers do?<\/h3>\n<p>garrisonOne&#8217;s penetration testing team uses real-world attack techniques to expose weaknesses in your network, applications, and cloud environment &#8212; then helps you fix them.<\/p>\n<a href=\"\/penetration-testing\" class=\"go-cta-btn\">Explore our pen testing services &#8594;<\/a>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Penetration testing is a controlled cyberattack on your own systems \u2014 done by experts you hire. Learn what it is, how it works, who needs it, and what to expect.<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[125],"tags":[128,127,126],"class_list":["post-10668","post","type-post","status-publish","format-standard","category-penetration-testing","tag-cybersecurity","tag-ethical-hacking","tag-pen-testing","entry"],"_links":{"self":[{"href":"https:\/\/garrisonone.com\/blog\/wp-json\/wp\/v2\/posts\/10668","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/garrisonone.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/garrisonone.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/garrisonone.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/garrisonone.com\/blog\/wp-json\/wp\/v2\/comments?post=10668"}],"version-history":[{"count":1,"href":"https:\/\/garrisonone.com\/blog\/wp-json\/wp\/v2\/posts\/10668\/revisions"}],"predecessor-version":[{"id":10669,"href":"https:\/\/garrisonone.com\/blog\/wp-json\/wp\/v2\/posts\/10668\/revisions\/10669"}],"wp:attachment":[{"href":"https:\/\/garrisonone.com\/blog\/wp-json\/wp\/v2\/media?parent=10668"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/garrisonone.com\/blog\/wp-json\/wp\/v2\/categories?post=10668"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/garrisonone.com\/blog\/wp-json\/wp\/v2\/tags?post=10668"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}