Hacking For Dummies. Kevin BeaverЧитать онлайн книгу.
the past, a lot of security assessment techniques involved manual processes. Now certain vulnerability scanners automate various tasks, from testing to reporting to remediation validation (the process of determining whether a vulnerability was fixed). Some vulnerability scanners can even help you take corrective actions. These tools allow you to focus more on performing the tests and less on the specific steps involved. Following a general methodology and understanding what’s going on behind the scenes will help you find the things that really matter.
Think logically — like a programmer, a radiologist, or a home inspector — to dissect and interact with all the system components to see how they work. You gather information, often in many small pieces, and assemble the pieces of the puzzle. You start at point A with several goals in mind, run your tests (repeating many steps along the way), and move closer until you discover security vulnerabilities at point B.
The process used for such testing is the same as the one that a malicious attacker would use. The primary differences lie in the goals and how you achieve them. Today’s attacks can come from any angle against any system — not just from the perimeter of your network and the Internet as you may have been taught in the past. Eventually, you’ll want to test every possible entry point, including partner, vendor, and customer networks, as well as home users, wireless networks, and mobile devices. Any human being, computer system, or physical component that protects your computer systems — both local and in the cloud — is fair game for attack, and it needs to be tested eventually.
Track what worked in previous tests and why.
Prove what you did.
Correlate your testing with firewalls, intrusion prevention systems (IPSes), and other log files if trouble or questions arise.
Document your findings.
Your main tasks are to find the vulnerabilities and to simulate the information gathering and system compromises carried out by someone with malicious intent — a partial attack on one computer, perhaps, or a comprehensive attack against the entire network. Generally, you look for weaknesses that malicious users and external attackers might exploit. Assess both external and internal systems (including processes and procedures that involve computers, networks, people, and physical infrastructures). Look for vulnerabilities. Check how all your systems interconnect and how private systems and information are (or aren’t) protected from untrusted elements.
These steps don’t include specific information on the methods that you use for social engineering and assessing physical security, but the techniques are the same. I cover social engineering and physical security in more detail in chapters 6 and 7, respectively.
As a security professional, you may not have to worry about covering your tracks or evading IPSes or related security controls because everything you do is legitimate, but you may want to test systems stealthily. In this book, I discuss techniques that hackers use to conceal their actions and outline some countermeasures for concealment techniques.
Seeing What Others See
Getting an outside look can turn up a ton of information about your organization and systems that others can see, and you do so through a process often called footprinting. Here’s how to gather the information:
Use a web browser to search for information about your organization. Search engines, such as Google and Bing, are great places to start.
Run network scans, probe open ports, and seek out vulnerabilities to determine specific information about your systems. As an insider, you can use port scanners, network discovery tools, and vulnerability scanners (such as Nmap, SoftPerfect Network Scanner, and GFI LanGuard) to see what’s accessible and to whom.
The amount of information you can gather about an organization’s business and information systems can be staggering and often widely available. Your job is to find out what’s out there. This process is often referred to as open-source intelligence (OSINT). From social media to search engines to dedicated intelligence-gathering tools, quite a bit of information is available on network and information vulnerabilities if you look in the right places. This information potentially allows malicious attackers and employees to access sensitive information and target specific areas of the organization, including systems, departments, and key people. I cover information gathering in detail in Chapter 5.
Scanning Systems
Active information gathering produces more details about your network and helps you see your systems from an attacker’s perspective. You can do the following things:
Use the information provided by WHOIS searches to test other closely related IP addresses and host names. When you map and gather information about a network, you see how its systems are laid out. This information includes determining IP addresses, host names (typically external but occasionally internal), running protocols, open ports, available shares, and running services and applications.
Scan internal hosts when they’re within the scope of your testing. (They really ought to be because that’s where the large majority of vulnerabilities exist.) These hosts may not be visible to outsiders (you hope they’re not), but you absolutely need to test them to see what rogue (or even curious or misguided) employees, other insiders, and even malware controlled by outside parties can access. A worst-case situation is that the intruder has set up shop on the inside. Just to be safe, examine your internal systems for weaknesses.