Basic networking concepts for Ethical hacking

We explain all the important Basic networking concepts for Ethical hacking.

Network

A collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information.

Types of Network

• LAN is in a small geographical area, such as a college or an office building
• WAN combination of multiple LANs
• WLAN links two or more devices using some wireless distribution method and usually providing a connection through an access point to the wider internet

Internet

A network of interlinked computer networking worldwide, which is accessible to the general public.

History of Internet

• 1969 -ARPANET was born 4 nodes were inter-connected, UCLA, SRI, UCSB, U. of Utah. Charley Kline from UCLA sent 1stpacket
• 1974 -TCP was invented by Vinton Cerf and Bob Kahn
• 1982 -DoDused TCP/IP to interconnect networks. Thus the Internet
• 1984 -DNS was introduced
• 1988 -First Internet worm released by Morris
• 1991 -WWW was created by Tim Berners-Lee
• 2011 -Internet users, 6,930,055,154 only

Server

IP Address

The numerical label assigned to devices, participating in-network that uses IP for communicating amongst themselves

serves two principal functions :

host/network interface identification

local addressing

DNS ( Domain Name System )

*A distributed hierarchical naming system for computers, services, or any resource connected to the Internet or a PVT. network

*translates domain names meaningful to humans into computer understandable IP address

*eg. : www.google.com-74.125.236.48

Port

*A logical number allows software applications to share hardware resources without interfering with each other.

*Example :

Programming Language

1. Artificial language designed to express computations that can be performed by a machine, particularly a computer
2. Programming Loopholes :
3. the flaws in the programming which can be exploited.
4. most of the attacks are nothing but loopholes of some kind.

Malware

Virus

*A program that attaches & self-replicates itself into host programs or data files

*Mostly triggered through user interaction, such as opening a file or running a program

*e.g.: Michelangelo, Stoned

Trojan horse

Non-replicating programs that run in the background of a legitimate-looking program

Worms

Self-replicating, self-contained programs, execute themselves, unlike viruses that need to attach

*Consumes space on the system

Phishing

Phishing is a way of attempting to acquire sensitive information such as usernames, passwords, and credit card details by masquerading as a trustworthy entity in an electronic communication.

Protection against phishing

Be suspicious of unsolicited phone calls, visits, or email messages.

*Do not provide personal information or information about your organization.

*Do not reveal personal or financial information in an email.

*Don’t send sensitive information over the Internet before checking a website’s security.

Modes of spreading?

• Email Attachments
• Rogue Websites
• Networks
• Infected Boot disks
• Phishing Schemes
• Infected Software
• Hackers
• Friends and Relatives

Session Hijacking and cookie grabbing

What is a session?

A session is a series of interactions between two communication endpoints that occur during the span of a single connection

What are cookies?

A computer cookie is a small text file that contains a unique ID tag, placed on your computer by a website.

Reading and writing cookie

*Reading:

javascript:alert(document.cookie);

*Writing:

javascript:document.cookie=’cookie data’;

Types of session hijacking:

*Active: In an active attack, an attacker finds an active session and takes over

*Passive: With the passive attack, an attacker hijacks a session but sits back, and watches and records all the traffic that is being sent forth

Tools for this:

*Ettercap

*Hamster

Email Hacking, Forging, and Tracing

Email Hacking

• Mostly Email account can be hacked through
• Phishing
• DNS Hijacking
• MITM Attack

Email Tracing

E-mail tracking is a method for monitoring the e-mail delivery to the intended recipient. E-mail tracking is useful when the sender wants to know if the intended recipient actually received the e-mail, or if they clicked the links.

Man-in-the-middle Attack

The attacker intercepts messages in a public key exchange and then retransmits them, substituting his own public key for the requested one, so that the two original parties still appear to be communicating with each other.

Backtrack Linux

A Linux distribution distributed as Live cd or Usb for penetration testing provides penetration testers a comprehensive collection of security-related tools, support live cd and live USB and permanent installation also.

XSS

Acronym for Cross-Site Scripting. A security breach that takes advantage of dynamically generated Web pages. In this attack, a Web application is sent with a script that activates when it is read by an unsuspecting user’s browser or by an application that has not protected itself against cross-site scripting

Damages due to XSS’s

• complete shutdown of the website including the defacement of the website.
• it can also steal useful information like username & passwords using this attack.
• the session can also be hijacked by cookie grabbing through XSS.

How to check for this vulnerability?

Enter <script>alert(‘xss’);</script> in the search box of the suspected web page if you will see the alert message saying XSS then this website is XSS vulnerable with high probability.

What else can be done after that?

You can inject the more dangerous script into the web page and make that page a kind of virus. Whoever will visit that page will provide their browser’s information or session information to the attacker.

Fake SMS & Calls

What is fake SMS or spoofed SMS

• You can get the SMS from your friend even if he has not sent the SMS
• Spoofing has both legitimate uses
• setting the company name from which the message is being sent or a product name

What is caller ID spoofing?

Caller ID spoofing is the practice of causing the telephone network to display a number on the recipient’s Caller IDdisplaythat is not that of the actual originating station. The term is commonly used to describe situations in which the motivation is considered malicious by the speaker or writer. Caller ID Spoofing*Using a Web-based spoofing service involves creating an account with a provider, logging in to their Website, and completing a form. Most companies require the following basic fields:

• source number
• destination number
• Caller ID number

Isn’t it a crime?

*Yes, In indiaspoofing a call or SMS is a crime

How to catch the spoofer?

*Launch the FIR and request the telecom service provider to give the detail of the caller

*It’s a very low probability that they can catch the exact person

Penalties against hacking in India

IT Act 2000

*This Act aims to provide the legal infrastructure for e-commerce in India

*cyber laws have a major impact on e-businesses and the new economy in India

*The Information Technology Act, 2000 also aims to provide for the legal framework so that legal sanctity is accorded to all electronic records and other activities carried out by electronic means

Punishment for violation of privacy

*shall be punished with imprisonment which may extend to three years or with fine not exceeding two lakh rupees, or with both

*also

Punishment for cyber terrorism

*Whoever commits or conspires to commit cyber terrorism shall be punishable with imprisonment which may extend to imprisonment for life

The section comes under cyber laws

*Section 67, 67B, 67C

*Section 68

*Section 69, 69B, 69C

*Section 70, 71, 72, 72A

*Section 73

Originally published at https://www.softwarequery.com.