Skills

As an ethical hacker, you will need to understand various hacking techniques such as −

Password guessing and crackingSession hijackingSession spoofingNetwork traffic sniffingDenial of Service attacksExploiting buffer overflow vulnerabilitiesSQL injection

In this article, we will discuss some of the skills that you would require to become an expert in Ethical Hacking.

Basic Skills

Computer Hacking is a Science as well as an Art. Like any other expertise, you need to put a lot of effort in order to acquire knowledge and become an expert hacker. Once you are on the track, you would need more effort to keep up-to-date with latest technologies, new vulnerabilities and exploitation techniques.

An ethical hacker must be a computer systems expert and needs to have very strong programming and computer networking skills.

An ethical hacker needs to have a lot of patience, persistence, and perseverance to try again and again and wait for the required result.

Additionally, an ethical hacker should be smart enough to understand the situation and other users’ mind-set in order to apply social engineering exploits. A good ethical hacker has great problem-solving skills too.

Courses & Certifications

This tutorial provides the basic guidelines to become a successful Ethical Hacker. If you want to excel in this field, then you might choose to pursue the following courses and certifications −

Obtain a bachelor’s degree in Computer Science or A+ Certificate to gain an understanding of the most common hardware and software technologies.

Get into a programmer’s role for a few years and then switch to get a tech support position.

Proceed to get network certifications like Network+ or CCNA and then security certifications like Security+, CISSP, or TICSA.

It is recommended that you get some work experience as a Network Engineer and System Administrator to understand networks and systems inside out.

Keep going through various books, tutorials and papers to understand various computer security aspects and take them as a challenge to secure your network and computer systems as network security engineer.

Study courses which cover creating Trojan horses, backdoors, viruses, and worms, denial of service (DoS) attacks, SQL injection, buffer overflow, session hijacking, and system hacking.

Master the art of penetration testing, footprinting and reconnaissance, and social engineering.

Finally go for a Certified Ethical Hacker (CEH) Certification.

GIAC (Global Information Assurance Certification) and Offensive Security Certified Professional (OSCP) are additional IT security certifications which will add a lot of value to your profile.

Final Note

You need to stay as a White Hat Hacker which means you need to work within given boundaries. Never intrude or attack any computer or network without a required permission from the authorities.

As a final note, it is highly recommended that you refrain from engaging yourself in black hat hacking which may spoil your entire career.

Sniffing is the process of monitoring and capturing all the packets passing through a given network using sniffing tools. It is a form of “tapping phone wires” and get to know about the conversation. It is also calledwiretapping applied to the computer networks.

There is so much possibility that if a set of enterprise switch ports is open, then one of their employees can sniff the whole traffic of the network. Anyone in the same physical location can plug into the network using Ethernet cable or connect wirelessly to that network and sniff the total traffic.

In other words, Sniffing allows you to see all sorts of traffic, both protected and unprotected. In the right conditions and with the right protocols in place, an attacking party may be able to gather information that can be used for further attacks or to cause other issues for the network or system owner.

What can be sniffed?

One can sniff the following sensitive information from a network −

Email trafficFTP passwordsWeb trafficsTelnet passwordsRouter configurationChat sessionsDNS traffic

How it works

A sniffer normally turns the NIC of the system to the promiscuous mode so that it listens to all the data transmitted on its segment.

Promiscuous mode refers to the unique way of Ethernet hardware, in particular, network interface cards (NICs), that allows an NIC to receive all traffic on the network, even if it is not addressed to this NIC. By default, a NIC ignores all traffic that is not addressed to it, which is done by comparing the destination address of the Ethernet packet with the hardware address (a.k.a. MAC) of the device. While this makes perfect sense for networking, non-promiscuous mode makes it difficult to use network monitoring and analysis software for diagnosing connectivity issues or traffic accounting.

A sniffer can continuously monitor all the traffic to a computer through the NIC by decoding the information encapsulated in the data packets.

Types of Sniffing

Sniffing can be either Active or Passive in nature.

Passive Sniffing

In passive sniffing, the traffic is locked but it is not altered in any way. Passive sniffing allows listening only. It works with Hub devices. On a hub device, the traffic is sent to all the ports. In a network that uses hubs to connect systems, all hosts on the network can see the traffic. Therefore, an attacker can easily capture traffic going through.

The good news is that hubs are almost obsolete nowadays. Most modern networks use switches. Hence, passive sniffing is no more effective.

Active Sniffing

In active sniffing, the traffic is not only locked and monitored, but it may also be altered in some way as determined by the attack. Active sniffing is used to sniff a switch-based network. It involves injecting address resolution packets (ARP) into a target network to flood on the switch content addressable memory (CAM) table. CAM keeps track of which host is connected to which port.

Following are the Active Sniffing Techniques −

MAC FloodingDHCP AttacksDNS

PoisoningSpoofing AttacksARP

Poisoning

Protocols which are affected

Protocols such as the tried and true TCP/IP were never designed with security in mind and therefore do not offer much resistance to potential intruders. Several rules lend themselves to easy sniffing −

HTTP − It is used to send information in the clear text without any encryption and thus a real target.

SMTP (Simple Mail Transfer Protocol) − SMTP is basically utilized in the transfer of emails. This protocol is efficient, but it does not include any protection against sniffing.

NNTP (Network News Transfer Protocol)− It is used for all types of communications, but its main drawback is that data and even passwords are sent over the network as clear text.

POP (Post Office Protocol) − POP is strictly used to receive emails from the servers. This protocol does not include protection against sniffing because it can be trapped.

FTP (File Transfer Protocol) − FTP is used to send and receive files, but it does not offer any security features. All the data is sent as clear text that can be easily sniffed.

IMAP (Internet Message Access Protocol) − IMAP is same as SMTP in its functions, but it is highly vulnerable to sniffing.

Telnet − Telnet sends everything (usernames, passwords, keystrokes) over the network as clear text and hence, it can be easily sniffed.

Sniffers are not the dumb utilities that allow you to view only live traffic. If you really want to analyze each packet, save the capture and review it whenever time allows.

Hardware Protocol Analyzers

Before we go into further details of sniffers, it is important that we discuss about hardware protocol analyzers. These devices plug into the network at the hardware level and can monitor traffic without manipulating it.

Hardware protocol analyzers are used to monitor and identify malicious network traffic generated by hacking software installed in the system.

They capture a data packet, decode it, and analyze its content according to certain rules.

Hardware protocol analyzers allow attackers to see individual data bytes of each packet passing through the cable.

These hardware devices are not readily available to most ethical hackers due to their enormous cost in many cases.

Lawful Interception

Lawful Interception (LI) is defined as legally sanctioned access to communications network data such as telephone calls or email messages. LI must always be in pursuance of a lawful authority for the purpose of analysis or evidence. Therefore, LI is a security process in which a network operator or service provider gives law enforcement officials permission to access private communications of individuals or organizations.

Almost all countries have drafted and enacted legislation to regulate lawful interception procedures; standardization groups are creating LI technology specifications. Usually, LI activities are taken for the purpose of infrastructure protection and cyber security. However, operators of private network infrastructures can maintain LI capabilities within their own networks as an inherent right, unless otherwise prohibited.

LI was formerly known as wiretappingand has existed since the inception of electronic communications.

Tools

In this chapter, we will discuss in brief some of famous tools that are widely used to prevent hacking and getting unauthorized access to a computer or network system.

NMAP

Nmap stands for Network Mapper. It is an open source tool that is used widely for network discovery and security auditing. Nmap was originally designed to scan large networks, but it can work equally well for single hosts. Network administrators also find it useful for tasks such as network inventory, managing service upgrade schedules, and monitoring host or service uptime.

Nmap uses raw IP packets to determine −

what hosts are available on the network,

what services those hosts are offering,

what operating systems they are running on,

what type of firewalls are in use, and other such characteristics.

Nmap runs on all major computer operating systems such as Windows, Mac OS X, and Linux.

Metasploit

Metasploit is one of the most powerful exploit tools. It’s a product of Rapid7 and most of its resources can be found at: www.metasploit.com. It comes in two versions − commercial and free edition. Matasploit can be used with command prompt or with Web UI.

With Metasploit, you can perform the following operations −

Conduct basic penetration tests on small networks

Run spot checks on the exploitability of vulnerabilities

Discover the network or import scan data

Browse exploit modules and run individual exploits on hosts

Burp Suit

Burp Suite is a popular platform that is widely used for performing security testing of web applications. It has various tools that work in collaboration to support the entire testing process, from initial mapping and analysis of an application's attack surface, through to finding and exploiting security vulnerabilities.

Burp is easy to use and provides the administrators full control to combine advanced manual techniques with automation for efficient testing. Burp can be easily configured and it contains features to assist even the most experienced testers with their work.

Angry IP Scanner

Angry IP scanner is a lightweight, cross-platform IP address and port scanner. It can scan IP addresses in any range. It can be freely copied and used anywhere. In order to increase the scanning speed, it uses multithreaded approach, wherein a separate scanning thread is created for each scanned IP address.

Angry IP Scanner simply pings each IP address to check if it’s alive, and then, it resolves its hostname, determines the MAC address, scans ports, etc. The amount of gathered data about each host can be saved to TXT, XML, CSV, or IP-Port list files. With help of plugins, Angry IP Scanner can gather any information about scanned IPs.

Cain & Abel

Cain & Abel is a password recovery tool for Microsoft Operating Systems. It helps in easy recovery of various kinds of passwords by employing any of the following methods −

sniffing the network,

cracking encrypted passwords using Dictionary, Brute-Force and Cryptanalysis attacks,

recording VoIP conversations,

decoding scrambled passwords,

recovering wireless network keys,

revealing password boxes,

uncovering cached passwords and analyzing routing protocols.

Cain & Abel is a useful tool for security consultants, professional penetration testers and everyone else who plans to use it for ethical reasons.

Ettercap

Ettercap stands for Ethernet Capture. It is a network security tool for Man-in-the-Middle attacks. It features sniffing of live connections, content filtering on the fly and many other interesting tricks. Ettercap has inbuilt features for network and host analysis. It supports active and passive dissection of many protocols.

You can run Ettercap on all the popular operating systems such as Windows, Linux, and Mac OS X.

EtherPeek

EtherPeek is a wonderful tool that simplifies network analysis in a multiprotocol heterogeneous network environment. EtherPeek is a small tool (less than 2 MB) that can be easily installed in a matter of few minutes.

EtherPeek proactively sniffs traffic packets on a network. By default, EtherPeek supports protocols such as AppleTalk, IP, IP Address Resolution Protocol (ARP), NetWare, TCP, UDP, NetBEUI, and NBT packets.

SuperScan

SuperScan is a powerful tool for network administrators to scan TCP ports and resolve hostnames. It has a user friendly interface that you can use to −

Perform ping scans and port scans using any IP range.

Scan any port range from a built-in list or any given range.

View responses from connected hosts.

Modify the port list and port descriptions using the built in editor.

Merge port lists to build new ones.

Connect to any discovered open port.

Assign a custom helper application to any port.

QualysGuard

QualysGuard is an integrated suite of tools that can be utilized to simplify security operations and lower the cost of compliance. It delivers critical security intelligence on demand and automates the full spectrum of auditing, compliance and protection for IT systems and web applications.

QualysGuard includes a set of tools that can monitor, detect, and protect your global network.

WebInspect

WebInspect is a web application security assessment tool that helps identify known and unknown vulnerabilities within the Web application layer.

It can also help check that a Web server is configured properly, and attempts common web attacks such as parameter injection, cross-site scripting, directory traversal, and more.

LC4

LC4 was formerly known asL0phtCrack. It is a password auditing and recovery application. It is used to test password strength and sometimes to recover lost Microsoft Windows passwords, by using dictionary, brute-force, and hybrid attacks.

LC4 recovers Windows user account passwords to streamline migration of users to another authentication system or to access accounts whose passwords are lost.

LANguard Network Security Scanner

LANguard Network Scanner monitors a network by scanning connected machines and providing information about each node. You can obtain information about each individual operating system.

It can also detect registry issues and have a report set up in HTML format. For each computer, you can list thenetbios name table, current logged-on user, and Mac address.

Network Stumbler

Network stumbler is a WiFi scanner and monitoring tool for Windows. It allows network professionals to detect WLANs. It is widely used by networking enthusiasts and hackers because it helps you find non-broadcasting wireless networks.

Network Stumbler can be used to verify if a network is well configured, its signal strength or coverage, and detect interference between one or more wireless networks. It can also be used to non-authorized connections.

ToneLoc

ToneLoc stands for Tone Locator. It was a popular war dialling computer program written for MS-DOS in the early 90’s. War dialling is a technique of using a modem to automatically scan a list of telephone numbers, usually dialling every number in a local area code.

Malicious hackers use the resulting lists in breaching computer security - for guessing user accounts, or locating modems that might provide an entry-point into computer or other electronic systems.

It can be used by security personnel to detect unauthorized devices on a company’s telephone network.

Hacker Types

Hackers can be classified into different categories such as white hat, black hat, and grey hat, based on their intent of hacking a system. These different terms come from old Spaghetti Westerns, where the bad guy wears a black cowboy hat and the good guy wears a white hat.

White Hat Hackers

White Hat hackers are also known asEthical Hackers. They never intent to harm a system, rather they try to find out weaknesses in a computer or a network system as a part of penetration testing and vulnerability assessments.

Ethical hacking is not illegal and it is one of the demanding jobs available in the IT industry. There are numerous companies that hire ethical hackers for penetration testing and vulnerability assessments.

Black Hat Hackers

Black Hat hackers, also known ascrackers, are those who hack in order to gain unauthorized access to a system and harm its operations or steal sensitive information.

Black Hat hacking is always illegal because of its bad intent which includes stealing corporate data, violating privacy, damaging the system, blocking network communication, etc.

Grey Hat Hackers

Grey hat hackers are a blend of both black hat and white hat hackers. They act without malicious intent but for their fun, they exploit a security weakness in a computer system or network without the owner’s permission or knowledge.

Their intent is to bring the weakness to the attention of the owners and getting appreciation or a little bounty from the owners.

Miscellaneous Hackers

Apart from the above well-known classes of hackers, we have the following categories of hackers based on what they hack and how they do it −

Red Hat Hackers

Red hat hackers are again a blend of both black hat and white hat hackers. They are usually on the level of hacking government agencies, top-secret information hubs, and generally anything that falls under the category of sensitive information.

Blue Hat Hackers

A blue hat hacker is someone outside computer security consulting firms who is used to bug-test a system prior to its launch. They look for loopholes that can be exploited and try to close these gaps. Microsoft also uses the term BlueHatto represent a series of security briefing events.

Elite Hackers

This is a social status among hackers, which is used to describe the most skilled. Newly discovered exploits will circulate among these hackers.

Script Kiddie

A script kiddie is a non-expert who breaks into computer systems by using pre-packaged automated tools written by others, usually with little understanding of the underlying concept, hence the term Kiddie.

Neophyte

A neophyte, "n00b", or "newbie" or "Green Hat Hacker" is someone who is new to hacking or phreaking and has almost no knowledge or experience of the workings of technology and hacking.

Hacktivist

A hacktivist is a hacker who utilizes technology to announce a social, ideological, religious, or political message. In general, most hacktivism involves website defacement or denialof-service attacks.

We have passwords for emails, databases, computer systems, servers, bank accounts, and virtually everything that we want to protect. Passwords are in general the keys to get access into a system or an account.

In general, people tend to set passwords that are easy to remember, such as their date of birth, names of family members, mobile numbers, etc. This is what makes the passwords weak and prone to easy hacking.

One should always take care to have a strong password to defend their accounts from potential hackers.

A strong password has the following attributes −

• Contains at least 8 characters.
• A mix of letters, numbers, and special characters.
• A combination of small and capital letters.

Dictionary Attack

In a dictionary attack, the hacker uses a predefined list of words from a dictionary to try and guess the password. If the set password is weak, then a dictionary attack can decode it quite fast.

Hydra is a popular tool that is widely used for dictionary attacks. Take a look at the following screenshot and observe how we have used Hydra to find out the password of an FTP service.

Hybrid Dictionary Attack

Hybrid dictionary attack uses a set of dictionary words combined with extensions. For example, we have the word “admin” and combine it with number extensions such as “admin123”, “admin147”, etc.

Crunch is a wordlist generator where you can specify a standard character set or a character set. Crunch can generate all possible combinations and permutations. This tool comes bundled with the Kali distribution of Linux.

Brute-Force Attack

In a brute-force attack, the hacker uses all possible combinations of letters, numbers, special characters, and small and capital letters to break the password. This type of attack has a high probability of success, but it requires an enormous amount of time to process all the combinations. A brute-force attack is slow and the hacker might require a system with high processing power to perform all those permutations and combinations faster.

John the Ripper or Johnny is one of the powerful tools to set a brute-force attack and it comes bundled with the Kali distribution of Linux.

Rainbow Tables

A rainbow table contains a set of predefined passwords that are hashed. It is a lookup table used especially in recovering plain passwords from a cipher text. During the process of password recovery, it just looks at the pre-calculated hash table to crack the password. The tables can be downloaded from http://project-rainbowcrack.com/table.htm


RainbowCrack 1.6.1 is the tool to use the rainbow tables. It is available again in Kali distribution.

Quick Tips

• Don’t note down the passwords anywhere, just memorize them.


• Set strong passwords that are difficult to crack.
• 
  
• Use a combination of alphabets, digits, symbols, and capital and small letters.


• Don’t set passwords that are similar to their usernames.