Which Penetration Test
Do You Actually Need?
There are six penetration testing types defined by their target (network, web app, mobile, cloud, wireless, social engineering) and three testing approaches (black box, white box, grey box) defined by how much information your tester receives. Understanding both dimensions is how you avoid the most common and expensive pen testing mistake: commissioning the wrong test.
Six targets. Three approaches. One decision framework.
The six types below are defined by what is tested (your network, your web application, your cloud environment). The three approaches further below are defined by how much context the tester is given (black box, white box, grey box). Both dimensions matter when scoping a penetration testing engagement. Select any card to explore the full service.
Network Penetration Testing
Find the paths an attacker would take through your network before they do.
Web Application Testing
The test clients and auditors ask for before they trust your application with their data.
Mobile App Testing
iOS and Android security assessment before your users bear the risk.
Cloud Penetration Testing
AWS, Azure, and GCP testing that goes beyond what your scanner already tells you.
Wireless Penetration Testing
Wi-Fi and radio frequency assessment for on-premises environments.
Social Engineering Testing
Phishing, vishing, and physical access testing to measure your human layer.
Not sure which test you need?
Our CREST-certified consultants will walk you through the options at no charge and with no obligation, so you can go back to your manager with a clear recommendation and a written scope.
Black Box vs White Box vs Grey Box
Your auditor asked about your testing approach. These three apply to any of the six test types above. The difference is how much context the tester is given before they begin.
Black Box
No information is given to the tester. Simulates an external attacker who has done no prior reconnaissance on your environment.
Grey Box
Partial information: user credentials, API documentation, basic network diagrams. Balances realism with efficiency. The recommended default for first and annual tests.
White Box
Full access to documentation, source code, architecture diagrams, and credentials. Maximum coverage in minimum time.
Which approach should you specify?
For most organisations commissioning their first or annual test, grey box is the recommended default. It gives the tester enough context to go deeper, faster, without the artificial constraints of a pure zero-knowledge exercise. Black box is appropriate when you need to demonstrate to a regulator that your controls hold against a realistic external attacker. White box is most valuable during development or when you want maximum vulnerability coverage in a fixed timeframe.
Which Test Fits Your Situation?
Match your environment to the right assessment. If you span multiple categories, a combined engagement is usually the most cost-effective option.
What to specify in your penetration testing requirements
When writing penetration testing requirements, specify:
- The test type by name
- The testing approach (black, white, or grey box)
- The scope (number of IP addresses, URLs, or user roles)
- The deliverable format (executive summary and technical report)
Precursor provides all four in writing before testing begins.
Testing is point-in-time.
Monitoring is continuous.
Pair any test type with our 24/7 Managed SOC. We feed your pentest findings directly into custom detection rules, actively hunting for exploitation between annual assessments.
Explore 24/7 Monitoring24/7 Threat Hunting
Continuous monitoring of your entire perimeter.
Custom SOC Rules
Alerts tuned to your specific pentest findings.
Real-time Containment
Immediate isolation before lateral movement.
Board Assurance
Prove identified risks are actively monitored.
Scope the Right Test
Tell us your environment, compliance requirements, and what triggered the need. We will recommend the right test type and approach in writing, with a fixed-price proposal within 24 hours.
Frequently Asked Questions
Common questions about penetration testing types, approaches, and how to choose the right assessment.
There are six main types of penetration testing defined by their target: network, web application, mobile application, cloud, wireless, and social engineering. Additionally, each test type can be conducted using one of three approaches (black box, white box, or grey box) depending on how much information the tester is given about your environment.
The three testing approaches (sometimes called types) in penetration testing are black box, white box, and grey box. Black box testing simulates an external attacker with no prior knowledge of your systems. White box testing gives the tester full access to documentation, source code, and credentials. Grey box testing provides partial information, typically user credentials or basic network diagrams, and is the most common approach for commercial engagements.
In black box penetration testing, the tester is given no prior information about your systems and must enumerate and attack your environment as an external attacker would. In white box penetration testing, the tester is given full access to documentation, architecture diagrams, source code, and credentials, enabling maximum coverage in minimum time. Grey box testing is a hybrid approach and is the most widely used in commercial pen testing engagements.
PCI DSS Requirement 11.3 requires both internal and external network penetration testing, as well as testing of segmentation controls. Web application penetration testing is also required if your cardholder data environment includes web-facing applications. Most PCI DSS pen tests are conducted using a grey box approach, with testing conducted at least annually or after significant infrastructure changes.
For most organisations, a web application penetration test (from £3,500) is the best starting point. It covers the attack surface most likely to be targeted by opportunistic attackers and satisfies most client vendor questionnaires, Cyber Essentials Plus, and PCI DSS Requirement 6.6. If you have on-premises infrastructure, pair it with an internal network test.
UK penetration testing costs between £2,500 and £30,000+ depending on scope and test type. A web application test costs £3,500 to £8,000. An external network test costs £2,500 to £10,000+. An internal network test costs £5,000 to £15,000. A full security assessment costs £15,000 to £30,000+. All Precursor engagements are fixed-price.