The Phases of Ethical Hacking
The process of ethical hacking
can be broken down into five distinct phases. Later in this book,
hacking software programs and tools will be categorized into each of
these steps.
An ethical
hacker follows processes similar to those of a malicious hacker. The
steps to gain and maintain entry into a computer system are similar no
matter what the hacker’s intentions are.
Phases of hacking
Phase 1: Passive and Active Reconnaissance
Passive reconnaissance involves gathering information about a potential
target without the targeted individual’s or company’s knowledge.
Passive reconnaissance can be as simple as watching a building to
identify what time employees enter the building and when they leave.
However, most reconnaissance is done sitting in front of a computer.
When hackers are looking for information on a potential target, they
commonly run an Internet search on an individual or company to gain
information. I’m sure many of you have performed the same search on your
own name or a potential employer, or just to gather information on a
topic. This process when used to gather information regarding a TOE is
generally called information gathering. Social engineering and dumpster
diving are also considered passive information-gathering methods. These
two methods will be discussed in more detail later in this chapter.
Sniffing the network is another means of passive reconnaissance and can
yield useful information such as IP address ranges, naming conventions,
hidden servers or networks, and other available services on the system
or network. Sniffing network traffic is similar to building monitoring: a
hacker watches the flow of data to see what time certain transactions
take place and where the traffic is going. Sniffing network traffic is a
common hook for many ethical hackers. Once they use some of the hacking
tools and are able to see all the data that is transmitted in the clear
over the communication networks, they are eager to learn and see more.
Sniffing tools are simple and easy to use and yield a great deal of
valuable information. An entire chapter in this book (Chapter 6,
“Gathering Data from Networks: Sniffers”) is dedicated to these tools,
which literally let you see all the data that is transmitted on the
network. Many times this includes usernames and passwords and other
sensitive data. This is usually quite an eye-opening experience for many
network administrators and security professionals and leads to serious
security concerns.
Active
reconnaissance involves probing the network to discover individual
hosts, IP addresses, and services on the network. This process involves
more risk of detection than passive reconnaissance and is sometimes
called rattling the doorknobs. Active reconnaissance can give a hacker
an indication of security measures in place (is the front door locked?),
but the process also increases the chance of being caught or at least
raising suspicion. Many software tools that perform active
reconnaissance can be traced back to the computer that is running the
tools, thus increasing the chance of detection for the hacker.
Both passive and active reconnaissance can lead to the discovery of
useful information to use in an attack. For example, it’s usually easy
to find the type of web server and the operating system (OS) version
number that a company is using. This information may enable a hacker to
find a vulnerability in that OS version and exploit the vulnerability to
gain more access.
Phase 2: Scanning
Scanning involves taking the
information discovered during reconnaissance and using it to examine the
network. Tools that a hacker may employ during the scanning phase
include
- Dialers
Port scanners
Internet Control Message Protocol (ICMP) scanners - Ping sweeps
- Network mappers
- Simple Network Management Protocol (SNMP) sweepers
- Vulnerability scanners
- Computer names
- Operating system (OS)
- Installed software
- IP addresses
- User accounts
Phase 3: Gaining Access
Phase 3 is when the real hacking
takes place. Vulnerabilities exposed during the reconnaissance and
scanning phase are now exploited to gain access to the target system.
The hacking attack can be delivered to the target system via a local
area network (LAN), either wired or wireless; local access to a PC; the
Internet; or offline. Examples include stackbased buffer overflows,
denial of service, and session hijacking. These topics will be discussed
in later chapters. Gaining access is known in the hacker world as
owning the system because once a system has been hacked, the hacker has
control and can use that system as they wish.
Phase 4: Maintaining Access
Once a hacker has gained access
to a target system, they want to keep that access for future
exploitation and attacks. Sometimes, hackers harden the system from
other hackers or security personnel by securing their exclusive access
with backdoors, rootkits, and Trojans. Once the hacker owns the system,
they can use it as a base to launch additional attacks. In this case,
the owned system is sometimes referred to as a zombie system.
Phase 5: Covering Tracks
Once hackers have been able to
gain and maintain access, they cover their tracks to avoid detection by
security personnel, to continue to use the owned system, to remove
evidence of hacking, or to avoid legal action. Hackers try to remove all
traces of the attack, such as log files or intrusion detection system
(IDS) alarms. Examples of activities during this phase of the attack
include
- Steganography
- Using a tunneling protocol
- Altering log files
Steganography, using tunneling protocols, and altering log files for purposes of hacking will be discussed in later chapters.
Identifying Types of Hacking Technologies
Many methods and tools exist for
locating vulnerabilities, running exploits, and compromising systems.
Once vulnerabilities are found in a system, a hacker can exploit that
vulnerability and install malicious software. Trojans, backdoors, and
rootkits are all forms of malicious software, or malware. Malware is
installed on a hacked system after a vulnerability has been exploited.
Buffer overflows and SQL injection are two other methods used to gain access into computer systems. Buffer overflows and SQL
These technologies and attack methods will each be discussed in later
chapters. Many are so complex that an entire chapter is devoted to
explaining the attack and applicable technologies.
Most hacking tools exploit weaknesses in one of the following four areas:
Operating Systems Many system administrators install operating systems with the default
settings, resulting in potential vulnerabilities that remain unpatched.
Applications Applications
usually aren’t thoroughly tested for vulnerabilities when developers
are writing the code, which can leave many programming flaws that a
hacker can exploit. Most application development is “feature-driven,”
meaning programmers are under a deadline to turn out the most robust
application in the shortest amount of time.
Shrink-Wrap Code
Many off-the-shelf programs come with extra features the common user
isn’t aware of, and these features can be used to exploit the system.
The macros in Microsoft Word, for example, can allow a hacker to execute
programs from within the application.
Misconfigurations Systems
can also be misconfigured or left at the lowest common security
settings to increase ease of use for the user; this may result in
vulnerability and an attack.
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