Black Box Penetration Testing: Process, Types & Checklist

Technical Reviewers
Updated: November 18th, 2024
12 mins read

With the cost of cybercrimes projected to reach $10.5 trillion by 2025, it’s vital to prevent cyberattacks proactively, and black box penetration testing is an important step in achieving the highest level of cyber security possible.

What is Black Box Pentesting?

A black-box pentest is conducted by a third-party testing service in which the security expert emulates hacker behavior without prior knowledge of the target system, except for publicly available information about the target.

The name “black box” suggests a penetration test’s dark, no-information starting point, and aims to find and exploit vulnerabilities in a system as an outsider. Before the testing, the security engineer would have no access to source code (other than publicly available code), internal data, the structure, or the application’s design. 

Black Box Pentest vs Complete Security Review

While black-box pentesting is not an alternative to a complete security review, it helps test the application from an end-user or a hacker’s perspective and can flag serious vulnerabilities in your web-facing assets, such as validation errors, information disclosure via error messages, server misconfigurations, etc.

Cost of a Black Box Pentest

Full-scale black-box pentesting by ethical hackers usually costs between $5,000 and $50,000 per test, usually being more affordable than white-box and gray-box pentests. These tests are more expensive due to the in-depth testing required in these pentests. 

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Why Astra is the best in pentesting?

  • We’re the only company that combines automated & manual pentest to create a one-of-a-kind pentest platform.
  • Vetted scans ensure zero false positives.
  • Our intelligent vulnerability scanner emulates hacker behavior & evolves with every pentest.
  • Astra’s scanner helps you shift left by integrating with your CI/CD.
  • Our platform helps you uncover, manage & fix vulnerabilities in one place.
  • Trusted by the brands you trust like Agora, Spicejet, Muthoot, Dream11, etc.
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Why Do You Need A Black-Box Pentest? 

1. Simulate Real-World Attacks

A black-box pentest accurately represents how a hacker could breach your system in the real world and helps you prevent it. You can ascertain vulnerabilities such as payment gateway escalation in your network or app that could lead to a cyber attack, which can only be detected by a pentest. 

2. Improve Your Security Posture

This type of penetration testing primarily finds all the exposed vulnerabilities in your apps and detects security issues stemming from interaction with the underlying environment (e.g., improper configuration files, unhardened OS, and applications). 

3. Detect Core Issues

Since a black box pentest tests the application at runtime, it can help you detect implementation issues and incorrect product builds (e.g., old or missing modules/files) and can also be executed before your product launches to ensure the highest security level.

benefits drawbacks of black box pentesting

Types Of Penetration Testing

Considering that black-box penetration testing isn’t thorough enough, this is where gray-box & white-box penetration testing comes in. To better understand these three penetration testing styles, let’s look at their differences.

Black-box vs Gray-box vs White-box Penetration Testing

FactorsBlack-Box Penetration TestingGray-Box Penetration TestingWhite-Box Penetration Testing
Intel of the target systemNo intel.Partial intel.Complete intel.
Environment testedTests only the exposed environment.
Tests exposed & internal environments.Thorough testing of all assets – external, internal, and code.
Depth of testingProvides a surface-level view of security posture.Fairly in-depth.
Very in-depth.
GuessworkConsists of guesswork, and hit & miss sessions.Very limited use of guesswork involved.
No guesswork involved.
AutomationAutomation is heavily used.Automation is used sparsely.
Automation is used only as an aid to the manual process.
Completion timeUnpredictable completion time.Predictable. Takes several days to a couple of weeks to complete.Predictable. Takes a couple of months to complete.
CostIs usually more affordable.Costs lie between the two extremes.Is costly.

White-Box

White-box penetration testing leverages full knowledge of the target system for an exhaustive examination of all external, internal, and code-level assets. 

Relying on manual testing augmented by automation to eliminate guesswork, white-box pentests typically require a few months to complete, making them the most expensive option of the three testing types. 

Cost: The pricing usually begins at approximately $30,000 for a white-box pentest.

Gray-Box

Gray-box penetrating testing equips the hacker with partial intel on the target’s internal systems, such as login credentials, and tests for exposed and hidden vulnerabilities.

This pentesting type provides a better picture of the system’s security and involves very limited guesswork while sparsely employing automation. The timeline for completing the test is quite predictable, and the price is in the mid-range of the three. 

Cost: The pricing usually starts at $12,000 for a gray-box pentest.

Astra Pentest is built by the team of experts that helped secure Microsoft, Adobe, Facebook, and Buffer


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Black-Box

A black-box pentest is conducted without any prior intel on the target system, aiming to test only the exposed environment, which can result in an incomplete representation of security vulnerabilities.

Black box employs more automation than the other two types of pentests and can have a slightly more unpredictable timeline.

Cost: It is usually the most affordable option, with the pricing starting at $5000. 

Considering the limitations of a black-box test, it’s important to choose a pentesting service that offers both black-box & gray-box penetration testing as part of a complete website VAPT plan

Astra Security provides a combination of these types of testing for a thorough analysis of your security posture. Black-box pentesting helps with your application’s regular pentest, which you can use at the pace of your code push cycle. 

The gray-box testing ensures that our security experts try to break into the application like hackers and investigate internal and external threats. All vulnerabilities are then reported on our Pentest dashboard, simplifying overall vulnerability management for both the tester and the client. 

6 Common Black-Box Penetration Testing Techniques

Black box penetration testing techniques

1. Fuzzing

Fuzzing bombards web interfaces with unexpected data (random or crafted) to expose weaknesses in input validation, also called ‘noise injection’. The process aims to trigger unusual program behavior, potentially revealing flaws in the software’s ability to handle invalid inputs.

2. Syntax Testing

Syntax testing is a process of testing the data input format used in a system, usually done by adding input containing garbage, misplaced or missing elements, illegal delimiters, etc. The aim is to determine the outcomes if the inputs deviate from the syntax.

3. Exploratory Testing

Exploratory testing is testing without any pre-formed test plan or expectation of a specific outcome. The idea is to let the outcomes or anomalies of one test guide another, which is especially helpful in black-box pentesting, where a big find may shape the whole test.

4. Data Analysis

Data Analysis in black-box pentest refers to the review of the data generated by the target application, and helps the tester understand the target’s internal functions. 

5. Test Scaffolding

Test Scaffolding is a technique to automate intended tests with tools which is a process that helps the tester find out critical program behavior otherwise not possible in manual testing. These tools usually include debugging, performance monitoring, and test management tools.

6. Monitoring Program Behavior

Monitoring program behavior helps the tester understand how the program responds. The tester may find unspecified symptoms that are indicative of underlying vulnerabilities while also using automation to save testers from manually checking for anomalies in program behavior.

Black-Box Pentesting Checklist

black box pentesting checklist

Based on the OWASP Top 10 vulnerabilities, here’s a checklist to ensure your black-box pentest covers all crucial areas:

Reconnaissance and Enumeration

  1. Analyze Networks: Scan networks for exposed ports, systems, and services.
  2. Investigate Web App Endpoints: Enumerate web application endpoints and directories to identify potential areas for further investigation.

Vulnerability Assessment and Exploitation

  1. Employ Automation: Use automated tools and manual testers to detect other vulnerabilities.
  2. Exploit Hidden Inputs: Attempt to find and exploit all the input fields, including hidden ones.
  3. Test For CVEs: Test for common web vulnerabilities such as SQL injection, Cross-Site Scripting (XSS), Cross-Site Request Forgery (CSRF), and insecure direct object references.
  4. Fuzzing: Perform fuzzing on input fields to identify potential buffer overflows or other input validation issues.
  5. Test For Other Vulnerabilities: Explore the application’s error-handling mechanisms for potential information disclosure or other vulnerabilities.
  6. LFI And RFI Testing: Test for file inclusion vulnerabilities, including Local File Inclusion (LFI) and Remote File Inclusion (RFI).
  7. Prevent Privilege Escalation: Test for server misconfigurations or vulnerabilities that may result in unauthorized access or privilege escalation.

Advanced Techniques and Security Validation

  1. Use Different Credentials: Attack using different credentials, including insecure default credentials or brute force.
  2. Intercept Sever-Client Communication: Try to intercept and modify communication between clients and servers.
  3. Check Application Resistance: Assess the application’s resistance to common evasion techniques, such as input filtering or web application firewalls.
  4. Ensure Data Encryption: Verify that sensitive data is properly encrypted in transit and at rest, and test for potential data leakage vulnerabilities.

Black-Box Penetration Testing Steps

A typical black-box pentest goes through these 5 stages:

Black box pentesting steps

1. Reconnaissance

Reconnaissance is the process of gathering preliminary information about the target system. The intel may include information like – IP addresses, email addresses, employee information, websites, exposed pain points, and so on.

2. Scanning & Enumeration

More reconnaissance is done during scanning and enumeration. The tester looks for more data about the target, such as types of running software, operating systems, versions, connected systems, user accounts, user roles, etc.

3. Vulnerability Discovery

With the above reconnaissance, the tester now looks for public vulnerabilities in the target systems & networks, including known CVEs in the system, versions, or third-party applications the target uses.

4. Exploitation

Exploitation is where the tester crafts a malicious request or social engineer to exploit the identified vulnerabilities. The goal of this step is to get to the heart of the system via the shortest route possible. 

5. Privilege Escalation

After entering the internal system, the security expert tries to escalate their access level to gain complete access to the system and database, also called Privilege Escalation.

3 Drawbacks Of Black-Box Penetration Testing

A black-box penetration test is an important component of application security testing. However, it does have some drawbacks: 

1. Limitations In Scope

In no circumstance should you trade off a comprehensive review of the source code and internal system for a black-box pentest because, on its own, it fails to provide a complete picture of the target’s security system.

Combined with grey-box and white-box pentesting, it can result in a more comprehensive review of your source code and internal system.

2. Misses Hidden Vulnerabilities

Vulnerabilities identified in a black-box penetration test indicate that the target system has a weak security build. However, the test does not highlight any other important security vulnerabilities. In that case, the vulnerabilities are hidden inside the internal systems and provide a false sense of security.

It’s vital to use a complete VAPT service provider to cover all bases and reduce the guesswork involved in black box pentesting.

3. Unpredictable Completion Time

The timeline for a black-box pentest can be either way. Depending on the tester’s expertise, the timeline to recon and identify a single vulnerability can range from minimal to several months.

To mitigate this, it’s best to get your pentest service provider to create a realistic roadmap and timeline that covers the entire VAPT plan. 

Black Box Penetration Testing Tools

1. Astra Security

Astra Security - Pentest Dashboard

Key Features:

  • Platform: SaaS
  • Pentest Capabilities: Continuous automated scans with manual tests 
  • Accuracy: Zero false positives
  • Compliance Scanning: PCI-DSS, HIPAA, ISO27001, and SOC2
  • Expert Remediation Assistance: Yes
  • Price: Starting at $1999/yr
  • Best Suited For: Holistic VAPT across assets

Astra Security’s manual pentesting service, combined with the vulnerability scanner, tests your application and network for exposed vulnerabilities by conducting 9300+ tests, including benchmarks like OWASP TOP 10 and SANS 25. 

The testing includes white box, gray box, web application, API, blockchain, and cloud penetration testing, as well as black box penetration testing. 

Astra’s automated scan is done alongside security experts manually conducting black-box pentests and emulating hacker behavior. We conduct static & dynamic code analysis, business logic testing, and payment gateway testing. 

We also provide vetted scans to ensure zero false positives, a scan-behind-login feature, and seamless integration into your CI/CD pipeline.

We provide vulnerability reports with detailed remediation guides along with access to a team of 2 to 10 security experts to help you with the fixes and 1-3 rescans, depending on the plan you opt for.

Astra Security features

2. Nikto

Nikto Open Source Dashboard

Key Features:

  • Target: Web applications and servers
  • Pentest Capabilities: Vulnerability and misconfiguration identification
  • Deployment Capabilities: Manual installation from source code
  • Accuracy: False positives are possible
  • Compliance Scanning: None
  • Expert Remediation Assistance: No
  • Price: Open-source tool
  • Best Suited For: Open-source VAPT for web apps and servers

Nikto is an open-source web server scanner that can be used to find possible vulnerabilities in web servers. It looks for unsafe files and programs, server and software misconfigurations, out-of-date web server software versions, and unprotected files and applications. Black box tests can be carried out using the open-source web server scanner Nikto to find security flaws in web servers.

3. OWASP WebScarab

OWASP WebScarab Dashboard

Key Features:

  • Target: Web apps & servers
  • Pentest Capabilities: Finds vulnerabilities & misconfigurations
  • Deployment Capabilities: Manual setup from source
  • Accuracy: May yield false positives
  • Compliance Scanning: None
  • Expert Remediation Assistance: No
  • Price: Free & open-source
  • Best Suited For: Web app/server VAPT

The Open Web Application Security Project (OWASP) created WebScarab, a tool for evaluating online security applications. It functions as a proxy, intercepting requests from web browsers and answers from web servers, and enabling users to change them.

Final Thoughts

As celebrated software engineer & author Boris Beizer said,

Software never was perfect and won’t get perfect. But is that a license to create garbage? The missing ingredient is our reluctance to quantify quality.

Black-box pentesting helps you test your application during development, testing, and production. Although it has drawbacks, it is still essential to have a thorough pentesting process to ensure security on all levels.

By itself, black-box penetration testing does not reveal everything wrong with the application’s security. Combining a black-box penetration test with other tests, such as source code review, increases its effectiveness.

FAQ

What is the timeline for a black-box pentest?

The timeline for Black-Box Pentesting is 7-10 days. The rescan after fixing the vulnerabilities takes 3 more days. The timeline may differ slightly based on the scope of the test.

Why is black box testing needed?

The unique hacker-style approach of a black-box pentest helps test the system for vulnerabilities that other tests might miss.

Is black box testing manual or automated?

Black box testing is primarily done manually, but more automated methods are now available that can be simultaneously used with manual testing.

Is black box testing illegal?

No, black box testing is not illegal. It’s a method of pentesting in which the tester emulates hacker behaviour to find vulnerabilities in clients’ systems.