Penetration Testing: A Step-by-Step Guide to Securing Your System

It would be an understatement that security is a top priority for almost any business that works with personal data. Whether it’s just gender and birthday or a phone number and bank account details, you must protect this information at all costs. If you neglect this side of your mobile app or website, people will never trust you enough to use your services. So paying attention to the ways you protect user data is the basic requirement of successful software development.

However, it’s hard to estimate the level of security in, let’s say, laboratory conditions. You will need to know how well data is protected before you release your solution. How to learn if your security measures are enough? Use penetration testing. It’s an efficient way to see if there are any breaches in your defense and quickly fix them.

In this article, we are about to discuss what penetration testing is, why it’s important, and how to efficiently apply it to your project. Stay tuned! 

What is penetration testing?

The first thing we want to do is define this type of testing. Penetration testing (or ethical hacking) is the process of assessing the state of software security (infrastructural systems, networks, mobile apps, and web platforms) by simulating a cyber-attack. Its goal is to identify and exploit vulnerabilities that could be potentially used by malicious parties to gain unauthorized access or damage the software.

Pen testing is an essential component of a comprehensive security program and is typically performed by security professionals who are trained in ethical hacking techniques. The final results can help you improve your security level by identifying and prioritizing vulnerabilities for your team to address. The most common approaches to pen tests include:

• Black box: The tester has no prior knowledge of the system and tries to access it as a stranger.

• White box: The tester knows everything about the system's internals.

• Gray box: This approach combines elements of both previous ways. 

Penetration testing provides valuable insights into the security of your application and helps your team better understand the risks they face from cyber-attacks.

Importance of pen tests for your business

If you search something like “cyber attacks news,”you’ll see that the most recent posts about hacked software are hours old. An enormous amount of systems, apps, and websites are getting attacked by criminals who want to steal and exploit sensitive information. No digital business is safe from them, so you also can become a potential target for a new cyber attack.

So, if you want to be prepared for any kind of possible threat, you need to conduct penetration testing. It will help you identify vulnerabilities that hackers could exploit, understand how to fix them, and then strengthen your defenses.

Penetration testing can also help you:

• Evaluate security controls: Estimate the effectiveness of your current security measures like firewalls, intrusion detection systems, and access controls.

• Measure compliance: See if your app follows the necessary regulations and industry standards (PCI-DSS, HIPAA, and ISO 27001).

• Mitigate risk: Predict and prepare for the risk of a successful cyber attack, which can result in data breaches, reputational damage, and financial loss.

• Improve incident response: Identify weaknesses in your incident response plan and provide an opportunity to test and improve it.

These points clearly state that pen testing is a valuable tool for any type of organization to assess and improve its cybersecurity posture and reduce the risk of a successful cyber attack.

Penetration testing steps

Now we can get to the most important part—how to correctly conduct penetration testing. Depending on your industry and software specification, the details of the process may differ, but the main strategy stays the same from project to project. Here are the pen testing steps our team follows:

Step 1: Pre-engagement activities

Any process related to software development starts with research and preparation. It will allow you and your team to ensure that the process will go smoothly, safely, and fast. Some of the key pre-engagement activities include:

• Scoping the engagement: You need to define the scope of what you need to test, whether it’s just a piece of code or the whole service. Also, your team will choose the testing methods and think about any limitations or constraints.

• Getting client authorization: Your team will need to obtain permission and authorization from you or other appropriate parties like the IT department, legal department, or senior management.

• Defining the rules of engagement: This is the organizational part where you and your team define the testing schedule, communication channels, and procedures for handling any discovered vulnerabilities. 

• Signing a non-disclosure agreement (NDA): The final step is directed to your protection as a business. The testing team should sign the NDA with you so any discovered issues will stay within the team and won’t be abused to cause damage to your software

Now we are ready to start collecting the necessary information about the target system.

Step 2: Information gathering

Information gathering is a critical phase in penetration testing. Basically, it involves collecting as much information as possible about the target. The information testers find provides them with a better understanding of the target platform and helps them start the search for vulnerabilities. The most common ways to collect the data are passive gathering and active gathering.

• Passive information gathering

This approach means that the tester acquires all possible information about the target system without directly interacting with it. In most cases, it involves researching publicly available information about your organization, its employees, or the software they use. Examples of sources are social media profiles, websites, or search engine results.

• Active information gathering

The name speaks for itself: This approach does the exact opposite of the previous one, and the testers here actively interact with the target system. The testing team usually uses tools like port scanners, network mappers, or vulnerability scanners to identify potential breaches in the defense. With this approach, it’s easier to detect activities testers perform, but the results will be more detailed and efficient.

• Tools and techniques for information gathering

There are several approaches used in information gathering during a penetration test. Here are some of the most common with examples of the appropriate tools:

1. WHOIS lookup: A tool used to query the WHOIS database for information about the domain name owner, registrar, and technical contacts.

2. Google dorking: A technique used to perform advanced Google searches to find sensitive information about the target, such as confidential files or login pages.

3. Port scanning: Technique to scan the target system or network for open ports and services with tools like Nmap.

4. Network mapping: Tools like Netdiscover or Fping identify hosts, network devices, and their respective IP addresses.

5. DNS enumeration: Software like DNSenum queries the DNS for information about the target domain and its subdomains.

6. Banner grabbing: Testers connect to an open port and retrieve the banner or version information with tools like Netcat.

7. Web application mapping: This involves using a tool like Burp Suite or OWASP ZAP to map out the web application and identify potential vulnerabilities.

These are just a few of the many options that can be used to collect data. The specific tools and techniques used will depend on the scope of the test and the information needed.

Step 3: Vulnerability analysis

The next step is analyzing the vulnerabilities found by testers during information gathering. It can be done either automatically, or manually.

• Automated vulnerability scanning

It’s a technique used in penetration testing to identify vulnerabilities in a system or network using specialized software tools. This approach allows testers to quickly and efficiently scan a large number of systems or networks for known vulnerabilities and potential weaknesses.

There are several benefits to using automated vulnerability scanning, including:

• Efficiency

• Accuracy

• Consistency

• Cost-effectiveness

It is important to note that automated scanning tools are not a replacement for manual testing or expert analysis. Instead, they are a useful complement to other testing techniques and can help to identify potential vulnerabilities that may need further investigation. Additionally, automated scanners can generate false positives or miss vulnerabilities, so it is important to review the results carefully and validate any potential issues before taking action.

• Manual vulnerability scanning

Manual scanning identifies vulnerabilities in a system or network through manual testing and analysis. Unlike automated vulnerability scanning, manual tests involve human expertise and intuition to identify vulnerabilities that may not be detectable by automated tools.

These tests require a high level of skill and expertise and are typically performed by experienced security professionals or ethical hackers. It is important to note that manual tests are time-consuming and can be resource-intensive but they can identify vulnerabilities that may be missed by automated scanning tools.

Manual testing is also useful for identifying new or previously unknown vulnerabilities that are not included in existing vulnerability databases. Additionally, it can provide a more in-depth understanding of the security posture which can be useful in developing a more comprehensive security strategy.

• Tools and techniques for vulnerability analysis

For automated testing, there are several tech stack options:

1. Nessus: A commercial vulnerability scanner that can be used to scan a wide range of systems and networks, including web applications, databases, and virtual environments.

2. OpenVAS: An open-source vulnerability scanner that can be used to scan networks for known vulnerabilities.

3. Burp Suite: A suite of tools used for web application security testing, including automated scanning for vulnerabilities.

4. Qualys: A cloud-based vulnerability management platform that includes an automated scanning tool.

Manual tests can be conducted with the following tools:

1. Nmap: A network exploration and port scanning tool that can be used to identify open ports, services, and operating systems on a target system or network.

2. Wireshark: A network protocol analyzer that can be used to capture and analyze network traffic to identify potential vulnerabilities.

3. SQLMap: An automated SQL injection tool that can be used to identify and exploit SQL injection vulnerabilities in web applications.

4. Hydra: A password-cracking tool that can be used to identify weak passwords on target systems.

Step 4: Exploitation and post-exploitation

This is the main part of the pentesting process. The attack goes into its active phase and testers are probing your software to see what you need to change. It involves the following steps: 

• Exploiting vulnerabilities: Exploitation could involve using password cracking, privilege escalation, or exploiting software vulnerabilities. The goal is to gain access to the system or network with escalated privileges, which will allow the tester to take control of the target and gather more sensitive information.

• Gaining access to the system: It’s a key objective of a penetration testing engagement, as it allows the tester to identify vulnerabilities and weaknesses in the system's security controls. 

• Maintaining access and escalating privileges: Once the tester is in the system, they can begin the post-exploitation phase of the engagement, which involves exploring the system to gather information and escalate privileges.

• Covering tracks and avoiding detection: During a penetration testing engagement, it’s important to cover tracks and avoid detection to ensure that the test remains a controlled and ethical exercise and to avoid causing any harm or damage to the target system or organization. It can be done by deleting logs, hiding files, spoofing IP addresses, and using anonymous or encrypted communication channels.

Step 5: Reporting and remediation

Once the testing is complete and the results have been analyzed, the next steps of penetration testing are to prepare a report and take appropriate remediation action. The report should provide a detailed description of the vulnerabilities identified during the testing, along with recommended steps for remediation. The steps in writing the report include:

• Writing the penetration testing report

• Presenting the findings to the client

• Prioritizing and categorizing the vulnerabilities

• Providing recommendations for remediation

The report should be presented clearly and concisely and should include details of the testing methodology, tools and techniques used, and any limitations or constraints that may have affected the testing.

The remediation process typically involves developing a plan of action to address the vulnerabilities identified during the testing. This may involve implementing software patches, reconfiguring network settings, updating passwords or access controls, or providing staff training to improve security awareness.

Types and methods of penetration testing

External testing

External penetration testing is a type of testing that is conducted from outside of an organization's network or infrastructure. The goal of external penetration testing is to identify vulnerabilities that could be exploited by an attacker to gain unauthorized access to the organization's systems, applications, or data.

Internal testing

Internal penetration testing is conducted from within an organization's network or infrastructure. The goal here is to identify vulnerabilities that could be exploited by an attacker who has already gained access to the organization's internal network, such as an employee with malicious intent or a hacker who has successfully breached the organization's perimeter defenses.

Blind testing

During blind penetration testing, the tester is provided with limited information about the target system or network. The tester is typically given only the name or IP address of the target system or network and is not provided with any additional information about the system's architecture, network topology, or security controls.

Double-blind testing

Double-blind penetration testing, also known as "unannounced testing" or "zero-knowledge testing," is a type of testing in which neither the tester nor the organization being tested has any prior knowledge or information about the testing.

Double-blind testing is designed to simulate a scenario in which an attacker has no prior knowledge or information about the target system or network, and can be particularly useful in identifying potential blind spots in an organization's security defenses. However, double-blind testing can also be more time-consuming and resource-intensive than other types of testing and requires careful planning and coordination to ensure that the testing is conducted safely and ethically.

Targeted testing

Targeted penetration testing is a type of testing that focuses on a specific area or system within an organization's network or infrastructure. This type of testing is typically conducted when the organization has identified a specific area of concern, such as a critical system or application, or when a vulnerability has been identified and needs to be further tested.

Penetration testing with Yellow: What can we do for you?

We can help you identify vulnerabilities and weaknesses in your organization's network and systems, including those that may be difficult to detect using automated vulnerability scanning tools. Once vulnerabilities have been identified, our team will provide recommendations and guidance on how to mitigate the identified risks, which can help reduce the likelihood of a security breach or data loss.

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Our experienced specialists will provide valuable insights into the security of your organization's network and systems, and help mitigate the risks associated with cyberattacks and data breaches.

To sum up

Penetration testing is a critical component of a comprehensive cybersecurity strategy, helping businesses identify and mitigate vulnerabilities in their network and systems, and improving their overall security posture. Engaging a qualified and experienced penetration testing company firm can provide valuable insights and recommendations to help businesses address security risks and avoid the damaging consequences of a security breach or data loss.