Penetration testing, also known as pen testing, is a simulated cyber attack on a computer system, network or web application to evaluate its security posture. The purpose of pen testing is to identify vulnerabilities that an attacker could exploit, and provide recommendations for remediation.
The five stages of a typical pen testing process are:
Reconnaissance: This stage involves gathering information about the target system and its network. The objective is to gather as much information as possible about the environment, such as IP addresses, domain names, names of systems and applications, and more. Tools that can be used for reconnaissance include search engines such as Google, social media sites like LinkedIn and Twitter, and network mapping tools like Nmap.
Scanning: In this stage, the pen tester uses automated tools to scan the target system for vulnerabilities and open ports. The scanner looks for known vulnerabilities in the software and operating systems, as well as misconfigurations in the network that could be exploited. Tools that can be used for scanning include Nmap, Nessus, OpenVAS, and others.
Gaining Access: In this stage, the pen tester uses the information gathered from the previous stages to attempt to gain unauthorized access to the target system. This may involve exploiting software vulnerabilities or exploiting weaknesses in the target's security configuration. Tools that can be used for this stage include Metasploit, Burp Suite, and others.
Maintaining Access: Once the tester has gained access, the focus is on maintaining that access and preserving the ability to control the system. This may involve installing backdoors, hiding files, or modifying system configurations to make it harder for the target to detect and remove the attacker's presence. Tools that can be used for maintaining access include Netcat, Cryptcat, and others.
Reporting: The final stage of the pen testing process is to document and report on the findings. The report should be comprehensive and detailed, and should include a description of the testing process, a detailed analysis of any vulnerabilities found, and recommendations for remediation. Tools that can be used for reporting include Microsoft Word, Google Docs, and others.
It is important to note that the pen testing process can be tailored to meet the specific needs and objectives of the engagement. For example, some pen testing engagements may focus on specific areas, such as the target's web application or mobile devices, while others may focus on the target's entire network and infrastructure. Additionally, the pen testing process may include additional stages or activities, depending on the specific requirements of the engagement.
Expanding on the stages above
Reconnaissance
Define the scope: Before starting the reconnaissance stage, it is important to define the scope of the engagement, including the target systems, applications, and networks that will be tested. This will help you focus your efforts and ensure that you gather only the information that is relevant to your objective.
Use search engines: Search engines like Google can be a great source of information about the target. You can search for the target's domain name, IP address, or other relevant information to gather information about the target's web presence. You can also use Google to find public documents, such as white papers, that may contain useful information about the target.
Scan social media sites: Social media sites like LinkedIn and Twitter can be a good source of information about the target and its employees. You can search for the target's employees, as well as its official pages, to gather information about the company, its structure, and its products.
Network mapping: Use network mapping tools like Nmap to gather information about the target's network and the systems that are connected to it. Nmap can be used to identify open ports and services, as well as the operating systems that are being used on the target's systems.
Use WHOIS: Use the WHOIS database to gather information about the target's domain name registration, including the registrar, the name of the domain owner, and the domain's creation and expiration dates.
Document your findings: It is important to keep a detailed record of all the information you gather during the reconnaissance stage. You can use a spreadsheet or a database to keep track of the information you gather, including the IP addresses, domain names, and names of systems and applications.
Analyze the information: Once you have gathered all the information, you can analyze it to determine the target's overall security posture and identify potential vulnerabilities. This information can be used to determine the best approach for the next stage of the penetration testing process.
It is important to note that the information gathered during the reconnaissance stage should not be used for malicious purposes. The objective of reconnaissance is to gather information to improve the target's security posture, and not to compromise the target's systems or steal sensitive information.
Scanning
Prepare the scanning environment: Before starting the scanning stage, it is important to prepare the environment in which the scans will be run. This may involve setting up a dedicated testing network, configuring the scanner to run in a virtual machine, and ensuring that the scanner has access to the target systems.
Choose the right tool: There are many different scanning tools available, each with its own strengths and weaknesses. When choosing a scanning tool, it is important to consider the type of scan you need to perform, as well as the complexity of the target system and its network. Some of the most commonly used scanning tools include Nmap, Nessus, and OpenVAS.
Configure the scanner: Once you have chosen the right tool, it is important to configure the scanner to meet your specific needs and objectives. This may involve setting up scan profiles, selecting the types of scans you want to run, and defining the target systems and networks that will be scanned.
Run the scan: Once the scanner is configured, you can run the scan by launching the tool and specifying the target systems and networks. The scanner will then start scanning the target for vulnerabilities and open ports, and will generate a report of its findings.
Analyze the results: Once the scan is complete, it is important to analyze the results to determine what vulnerabilities and weaknesses were identified. You can use the results of the scan to prioritize the remediation of the most critical vulnerabilities and to determine the best approach for the next stage of the penetration testing process.
Document the results: It is important to keep a detailed record of all the information gathered during the scanning stage, including the results of the scan, the types of scans run, and the configuration of the scanner. This information can be used to validate the results and to provide a comprehensive report of the findings.
Repeat the scan: After the vulnerabilities and weaknesses have been remediated, it is important to repeat the scan to verify that the remediation was effective. This will help ensure that the target system and its network are secure and will help you identify any new vulnerabilities that may have been introduced.