The process of network penetration testing involves evaluating the security of a computer network infrastructure to identify vulnerabilities and weaknesses that could be exploited by malicious actors. By conducting thorough testing, administrators can discover open ports, troubleshoot live systems and services, and obtain system banners. This checklist serves as a guide to ensure that all necessary steps are taken to close unused ports, hide or customize banners, troubleshoot services, and calibrate firewall rules.
First and foremost, host discovery is essential to gather information about the target system. This phase involves DNS footprinting, which helps enumerate DNS records such as A, MX, NS, SRV, PTR, SOA, and CNAME. These records provide crucial information about the target domain, including its IP address, email exchange, DNS servers, services hosted, reverse DNS lookup, and DNS zone information. Network scanning tools like Advanced IP scanner, NMAP, HPING3, and NESSUS can be used to detect live and accessible hosts within the target network. Ping and ping sweep commands can be executed to scan specific IP addresses, ranges of IP addresses, wildcard addresses, or entire subnets. Whois information can also be obtained to learn more about a website, including its registration details and name servers. Traceroute can be used to display the route path and transit delay for packets, providing insights into network connectivity.
Once host discovery is complete, port scanning is performed using tools such as Nmap, Hping3, Netscan tools, and Network monitor. Port scanning helps identify open ports, which can serve as gateways for attackers to enter the network and install malicious backdoor applications. Specific ports, a range of ports, or even all ports can be scanned using commands. Online tools like YouGetSignal and Pentest-Tools.com can also assist in port scanning.
Banner grabbing and OS fingerprinting allow testers to determine the operating system of the target host and find potential vulnerabilities. Telnet, IDServe, and Nmap are commonly used tools for this purpose. By knowing the version and OS, testers can proceed to find vulnerabilities and exploit them to gain control over the system. Online tools like Netcraft, W3DT.net, and Shodan.io can provide additional information and insights.
After gathering all necessary information, vulnerability scanning is performed using tools such as GFI Languard, Nessus, Ratina CS, and SAINT. These scanners help identify vulnerabilities in the target and operating systems, providing insights into potential security loopholes. The process typically involves data gathering, host identification, port scanning, plugin selection, and reporting of data. By documenting all findings from penetration testing, administrators can effectively plan counteractions and address any identified vulnerabilities in their network. Network diagrams can also be drawn to visualize the logical connection path to the target host, allowing for better understanding of the network infrastructure.
Proxies can act as intermediaries between networking devices, protecting the local network from external access. Proxies like Proxifier, SSL Proxy, and Proxy Finder can be utilized to anonymize web browsing and filter unwanted content. Finally, it is crucial to document all findings from the penetration testing process, as this will help in identifying potential vulnerabilities and planning appropriate counteractions.
By following this comprehensive checklist, administrators can ensure that their network is thoroughly tested for vulnerabilities and weaknesses. The process of network penetration testing plays a vital role in assessing the security posture of a network and preventing potential security breaches that could lead to significant losses in terms of value and finance. By staying updated with the latest cybersecurity tools and techniques, organizations can better protect their networks and mitigate potential risks.