Continuation of Ethical Hacking Basics Session 1 & 2
The Transmission Control Protocol/Internet Protocol (TCP/IP) suite is so dominant and important to ethical hacking that it is given wide coverage in this lesson. Many tools, attacks, and techniques that will be covered throughout this class are based on the use and misuse of TCP/IP protocol suite. Understanding its basic functions will advance your security skills. This lesson also spends time reviewing the attacker’s process and some of the better known methodologies used by ethical hackers.
The Attacker’s Process
Objective:
State the process or methodology hackers use to attack networks
Attackers follow a fixed methodology. To beat a hacker, you have to think like one, so it’s important to understand the methodology. The steps a hacker follows can be broadly divided into six phases, which include pre-attack and attack phases:
- Performing Reconnaissance
- Scanning and enumeration
- Gaining access
- Escalation of privilege
- Maintaining access
- Covering tracks and placing backdoors
NOTE
A denial of service (DoS) might be included in the preceding steps if the attacker has no success in gaining access to the targeted system or network. Let’s look at each of these phases in more detail so that you better understand the steps.
Performing Reconnaissance
Reconnaissance is considered the first pre-attack phase and is a systematic attempt to locate, gather, identify, and record information about the target. The hacker seeks to find out as much information as possible about the victim. This first step is considered a passive information gathering. As an example, many of you have probably seen a detective movie in which the policeman waits outside a suspect’s house all night and then follows him from a distance when he leaves in the car. That’s reconnaissance; it is passive in nature, and, if done correctly, the victim never even knows it is occurring.
Hackers can gather information in many different ways, and the information they obtain allows them to formulate a plan of attack. Some hackers might dumpster dive to find out more about the victim. Dumpster diving is the act of going through the victim’s trash. If the organization does not have good media control policies, many types of sensitive information will probably go directly in the trash. Organizations should inform employees to shred sensitive information or dispose of it in an approved way.
Don’t think that you are secure if you take adequate precautions with paper documents. Another favorite of the hacker is social engineering. A social engineer is a person who can smooth talk other individuals into revealing sensitive information. This might be accomplished by calling the help desk and asking someone to reset a password or by sending an email to an insider telling him he needs to reset an account.
If the hacker is still struggling for information, he can turn to what many consider the hacker’s most valuable reconnaissance tool, the Internet. That’s right; the Internet offers the hacker a multitude of possibilities for gathering information. Let’s start with the company website. The company website might have key employees listed, technologies used, job listings probably detailing software and hardware types used, and some sites even have databases with employee names and email addresses.
Scanning and Enumeration
Scanning and enumeration is considered the second pre-attack phase. Scanning is the active step of attempting to connect to systems to elicit a response. Enumeration is used to gather more in-depth information about the target, such as open shares and user account information. At this step in the methodology, the hacker is moving from passive information gathering to active information gathering. Hackers begin injecting packets into the network and might start using scanning tools such as Nmap. The goal is to map open ports and applications. The hacker might use techniques to lessen the chance that he will be detected by scanning at a very slow rate. As an example, instead of checking for all potential applications in just a few minutes, the scan might take days to verify what applications are running. Many organizations use intrusion detection systems(IDS) to detect just this type of activity. Don’t think that the hacker will be content with just mapping open ports. He will soon turn his attention to grabbing banners. He will want to get a good idea of what type of version of software applications you are running. And, he will keep a sharp eye out for down-level software and applications that have known vulnerabilities. An example of down-level software would be Windows 95.
One key defense against the hacker is the practice of deny all. The practice of the deny all rule can help reduce the effectiveness of the hacker’s activities at this step. Deny all means that all ports and applications are turned off, and only the minimum number of applications and services are turned on that are needed to accomplish the organization’s goals.
Unlike the elite black hat hacker who attempts to remain stealth, script kiddies might even use vulnerability scanners such as Nessus to scan a victim’s network. Although the activities of the black hat hacker can be seen as a single shot in the night, the script kiddies scan will appear as a series of shotgun blasts, as their activity will be loud and detectable. Programs such as Nessus are designed to find vulnerabilities but are not designed to be a hacking tool; as such, they generate a large amount of detectable network traffic.
TIP
The greatest disadvantage of vulnerability scanners is that they are very noisy.
No comments:
Post a Comment