Uncovering Vulnerabilities: A Comprehensive Guide to Penetration Testing in Cybersecurity

No one is free from the prying eyes of hackers; because of software flaws or system vulnerabilities, there have been several instances of people or organizations becoming the target of hackers. In the first half of 2022, there were 236.1 million ransomware attacks worldwide, according to the AAG statistics report. Hackers are actively targeting devices and business websites to find vulnerabilities in an effort to uncover software flaws and carry out their malevolent intent, which may be motivated by fame or financial gain. For instance, a common method by which hackers gain access to computers is via malware, wherein the victim's computer is infected with malicious links or attachments. When these links or attachments are accessed, they can lead you to malicious sites or lock up important files.

There are many ways to prevent oneself from falling into the hands of attackers, and methods such as MFA (multi-factor authentication), strong passwords, etc. can help secure our devices from numerous types of cyberattacks. However, cyberattacks are not going to stop anytime soon, and the more companies develop software to prevent them, e.g., anti-malware, firewalls, encryption tools, etc., the more hackers find ways to breach the systems. Because hackers are always coming up with creative ways and methods to gain unauthorized access to vulnerable systems and data, businesses or corporations must enforce security measures, one of which is called penetration testing. Penetration testing, or “ethical hacking,” as it is commonly referred to, involves authorized attempts to exploit vulnerabilities in computer systems, networks, or applications to secure the computer or network system.

In this article, we’ll explore penetration testing, addressing its concepts, stages, tools, and importance for digital data.

Though it is a type of ethical hacking, penetration testing, also known as pen testing, is frequently confused with ethical hacking. Ethical hacking involves locating vulnerabilities in computers and information systems using the objectives and actions of malicious attackers (e.g., red hat hackers). This type of hacking is performed with the knowledge of the parties involved. Ethical hackers create scripts to test the vulnerability of a system and the complexity of the vulnerability, which are reported to the client so that vulnerabilities can be patched. Other tasks performed by ethical hackers include;

• Perform a risk assessment to find out the consequences of a breached system.
• Configuring security and developing tools to tighten security.
• Set up security policies e.g. administrative policies like password standards to prevent hackers from accessing devices/data.
• Train employees on network security

Typically, a vulnerability assessment is carried out before penetration testing; this is where a scanning tool is used to identify probable vulnerabilities in an organization. After the vulnerability test has identified vulnerabilities in a system, a penetration test is then carried out. Penetration testing is simply defined as ethical hacking that involves penetrating information systems. To do this, a number of techniques are utilized, such as phishing, password cracking, DOS (Denial of Service) attacks, network scanning attacks, wireless network assaults, privilege escalation, etc.

Through contractual agreements, ethical hackers are used to test the security of a system; this practice is used since it increases the effectiveness of the security system to hire someone who is not familiar with it. Ethical hackers, in contrast to people who are already familiar with the security infrastructure, approach the system from a new angle and are not restricted by familiarity. However, this may not always be the case, as there are different types of penetration testing, some of which may involve sharing certain information with the pentester in order for a test to be carried out.

Various areas are often examined as part of a penetration test to gauge a system's security. These areas include:

Network Services: The hacker seeks to find vulnerabilities in the security of the network infrastructure or devices on a particular network. Network mapping and scanning are carried out to evaluate the security of devices, servers, routers, outdated software, weak passwords, network services, etc.

Web application: Web-based applications are assessed to identify performance and security weaknesses. Some vulnerabilities may include; cross-site scripting, compliance testing, broken authentication, etc.

APIs (application programming interfaces): The hacker seeks to perform attacks against APIs because they expose data to a third-party user. There are several tests required to carry out API tests e.g. authentication bypassing, cross-user data requests, security misconfiguration, etc.

Wireless Networks: Wireless networks are prevalent in most organizations, and they create room for vulnerabilities. Examples of tests that can be performed against wireless networks include; weak encryption cracking, key cracking, packet injection, etc.

Social engineering: Employees within an organization also present a risk; therefore, phishing attack, a type of social engineering attack, is used to deceive employees into disclosing sensitive information. Employees receive emails with malicious links or attachments that are disguised as legitimate documents. The recipients of these emails are directed to a credential-harvesting website that harvests credentials in order to obtain private information.

To achieve a thorough assessment of the system's security, penetration testing normally follows a set of procedures. These phases consist of:

Reconnaissance: This phase focuses on learning as much as possible about the target. It enables the hacker or security expert to comprehend the toolset and method required to carry out an attack, which may include learning things like a system's network architecture, the type of operating system used, email addresses/passwords, employee information, etc. In order to accurately capture data and retrieve information quickly throughout the testing process, all client-related information is acquired and saved in a database.

Scanning and Enumeration: This phase focuses on identifying live machines on the network, scanning for open ports, which are an entry point for most hackers, and identifying vulnerabilities within the processes. After the scanning process, the type of attack that should be carried out will be determined.

Gaining Access or Exploitation: At this stage, once the information has been gathered and vulnerabilities have been identified, the system's vulnerability or security flaw is exploited to gain access to the data.

Maintaining Access: Once access is gained, the security hacker maintains persistence by ensuring that there’s a way to gain access to the system repeatedly. The hacker then deletes traces of activities and covers tracks so that the system can be explored thoroughly. The hacker also escalates privilege by extracting sensitive data, etc., to see the potential damage an actual attack could cause.

Penetration testing refers to a variety of techniques or methods for assessing a system's security. Penetration testing can take many different forms, including:

1. White box penetration test
2. Grey box penetration test
3. Black box penetration test

White-box Penetration Test

A white box penetration test, also known as a “clear box test," involves carrying out a security assessment with full knowledge of the workings of the system. In this case, the tester is aware of the fundamentals or operations of the system. Understanding the entire system's architecture or design gives the tester helpful insights.

Grey-box Penetration Test

A grey-box penetration test is the “in-between” which means that it possesses qualities of both white and black-box testing. In this case, the pentester is given access to some functionality or information about the system architecture, and testing is carried out based on the available information. The penetration tester has to gather more information that’ll help in creating real-world attacks to identify vulnerabilities that may not be obvious from an external view.

Black-box Penetration Test

The black-box test imitates an attack from an external point of view. This type of testing is performed by the hacker without knowing the infrastructure of the system. The tester simply goes in blindly to try to find vulnerabilities like a malicious hacker would, and exploit the system by performing a network penetration test, web application test, wireless network test, etc.

Kali Linux is a popular operating system common among hackers who target computer systems due to its toolset, which includes features for penetration testing and security auditing. It is open source, which means that it can be modified and customized to create specific attacks. It contains over 600 tools that can be used for numerous security tasks, e.g., digital forensics and security auditing. Examples of tools pre-installed on the operating system are;

1. Hydra: is a tool login cracker tool that performs brute force and dictionary attacks, allowing penetration testers to gain access from a remote to a system.

2. Nmap: Network Mapper (Nmap) is an open-source network scanner used for network discovery and security auditing. It efficiently locates accessible hosts on a network, ascertains the services those hosts are providing, and even offers insights into the operating systems those hosts are running by using IP packets. This effective tool is useful for determining network security and compiling crucial data regarding the target network infrastructure.

3. OWASP Zap: Open worldwide application security project Zed attack proxy is a web application security scanner that helps detect vulnerabilities in web applications.

4. Aircrack-ng: This is a set of tools used to scan and hack wifi networks. It performs packet capturing, cracking encryption, conducts wireless attacks, etc.

5. John the Ripper: This password-cracking tool designed to detect weak passwords performs brute-force attacks, dictionary attacks, etc. In other words, it breaks into a password-protected computer, network, or IT assets.

These tools are just a fraction of the tools available for penetration testing, the necessary tools are usually selected based on the requirements of the penetration tester.

There are consequences that arise when an organization's system is breached and under the attack of a hacker. Sensitive information can be exploited for numerous reasons, and companies or organizations may lose money, incur legal and regulatory repercussions, lose their reputation, and overall cause operational disruption. Penetration testing allows organizations to replicate attacks to help them discover vulnerable systems and ways that they can be fixed to void real-life attacks, so as to safeguard their systems and sensitive data.