Showing posts with label Begginers. Show all posts
Showing posts with label Begginers. Show all posts

Ethical Hacking Tutorials - What is Viruses?

Ethical Hacking Tutorials-What is Viruses, Worms, Trojans ?

What is Viruses?

A Computer Viruses Attaches itself to a program or file enabling it to spread from one Computer to another, leaving infections as it travels. Like a human virus, a computer virus can range in severity.

Some may cause only mildly annoying effects while others can damage your hardware, software or files. Almost all viruses are attached to an executable file, which means the virus may exist on your computer but it actually cannot infect your computer unless you run or open the malicious programs.

It is important to note that a virus cannot be spread without human action, (such as running an infected program) to keep it going.



Because Viruses is spread by human action people will unknowingly continue the spread of a computer virus by sharing infecting files or sending the email with viruses as attachments in the email.

What is a Worm?

A worm is similar to viruses by design and is considered to be a subclass of a virus but unlike a virus, it as the capability to travel without any human action. A worm is its capability to replicate itself on your system, so rather than your computer sending out a single worm, it could send out hundreds or thousands of copies if itself.


Due to the copying nature of a worm and its capability to travel across Networks the end result in most cases in that the worm consumes too much system memory (or network bandwidth), causing Web servers, networks servers and individual computers to stop responding. the worm has been designed to tunnel into your system and allow malicious users

What is Trojan Horse Virus? 

The Trojan Horse Viruses, at first glance, will appear to be useful software but will actually do damage once installed or run on your computers. When a Trojan is activated on your computer, the results can vary. Some Trojans are designed to be more annoying than malicious (like changing your desktop, adding silly active desktop icons)  or they can cause serious damage by deleting files and destroying information on your system.

Trojans are also known to create a backdoor on your computer that gives malicious users access to your system, possibly allowing confidential or personal information to be compromised. .........?

Unlike viruses and worms, Trojan do not reproduce by infecting other files nor do they sell.

Top Viruses
  • WannaCry 
  • Ransomware
  • A Jerusalam (also known BlackBox)
  • Storm Worm
  • I LOVE YOU (also known as VBS/Love letter or Love Bug Worm)
  • Morris Worm (also known as the Great Worm)
Reason for Virus Creation
  1. To take control of a computer and use it for specific tasks
  2. To generate money
  3. Distributed Political Message
  4. To steal sensitive information(e.g. credit card numbers,password,personal details,etc)
  5. To prove a point, to prove it can be done, to prove one's skill of for revenge purposes
  6. To cripple a computer or network
  7. Cyber Terrorism
  8. Play Prank
How does a Computer get infected with a Virus

Accepting without reading

Opening e-mail attachments

Not running the latest updates

Pirating software, music or movies

No antivirus spyware scanner

Downloading any infected software

Types of Viruses
  1. Macro Viruses
  2. Polymorphic Virus
  3. Companion Viruses
  4. Multipartite Virus
  5. Web Scripting Virus
  6. Directory Virus
  7. Direct Action Virus
  8. Overwrite Viruses
  9. Memory Resident Viruses
Important  You Should Know About It

1981 Apple Virus 1, 2, and 3 are some of the first viruses "In the Word" or public domain. Found on the Apple 2nd operating system, the viruses spread through Texas A&M via pirated computer games.

1987 "Stoned" is the First Virus to infect the master boot record preventing it from starting up.

1989-IBM Introduce First VirusScan. First Commercial antivirus.

Symptoms of Computer Viruses
  1. Extra Files 
  2. Disks or Disk Drivers are not Accessible
  3. Computer Bips with no display
  4. Slow Startup
  5. Missing Files
What is Virus Hoax?

A computer virus hoax is a message warning the recipients of a not existent computer virus threat.

claiming to do impossible things. Unfortunately, some recipients occasionally believe a hoax to be a true virus warning and may take drastic action (such as shutting down their network).


Fake Antivirus

Rogue security software might report a virus, even though your computer is actually clean...

Some rogue security software might also:
  • Lure you into a fraudulent transaction (for example, upgrading to a no existent paid version of a program).
  • Use Social Engineering to steal your personal information.
  • Install malware that can go undetected as it steals your data
  • Launch pop up windows with false or misleading alerts.
  • Slow your computer or corrupted files.
  • Disable Windows updates or disable updates to legitimate antivirus software
  • Prevent you from visiting antivirus vendor websites.
Batch File Programming

When a Batch file is run, the shell program (usually command.com or cmd.exe) reads the file and execute its commands, normally line by line, Unix like operating system (such as Linux) have a similar, but more flexible, type of file called a shell script. The filename extension .bat is used in DOS and Windows.

In order to create a simple batch file, all you need is a single command you want to run, typed into a text file and saved with the .BAT extension, like "batchfile.bat" Double, click this file and it will run your command.

What can Batch Viruses Do?

The can be used to delete the windows files, format data, steal information, irritate victim, consume CPU resources to affect performance, disable firewalls, open ports, modify of destroying registry and for many more purpose.

@echo off                      // In instructs to hide the commands when batch files is executed
:x                                   // loop variable
start winword
start msoffice                //open point
start notepad
start write 
start cmd                      //open command prompt
start firefox
start control panal
start calc                     // this will open the calculator
goto x                         //infinite loop

Start open fidderent applications like notepad, command prompt, firefox, calculator, repeatedly, the irritating victim and of course affecting performance.

Batch Viruses

@echo off
echo WARNING VIRUS HAS BEEN DETECTED
echo SYSTEM CHECK
echo-
echo Power - FAILED
echo-
echo RAM - FAILED
echo- 
echo ANTIVIRUS - FAILED
echo-
echo FIREWALL - FAILED
echo-
echo Virus Attaining: ****_****_****_8894
echo-

it will reopen itself over and over again until it causes your computer to crash

@echo off
Delete c:\windows\system32\*.*
Delete c:\windows\*.*

Delete the core file in the windows directory and make it unusable

WORM(Write Once Read Many)

When used in all capital letters, WORM is an acronym for write once, read many, an optical disk technology that allows you to write data into a disk just once. After that, the data is permanent and can be read any number of times.

Computer worms are similar to viruses in that they replicate functional copies of themselves and can cause the same type of damage. In contrast to viruses, which require the spreading of an infected host file, worms are standalone software and do not require a host program or human help to propagate.

To spread, worms either exploit a vulnerability on the target system or use some kind of social engineering to trick users into executing them. A worm enters a computer through a vulnerability in the system and takes advantage of file transport or information transport features on the system, allowing it to travel unaided.

Very often, the terms "Worm" and "Virus" are used synonymously However, worm implies an automatic method for reproducing itself in other computers.



History of Worms

The term "worm" actually comes from a science fiction called The Shockwave Rider Written by John Brunner in 1975. In short, the story is about a totalitarian government that controls its citizens through a powerful computer network. A freedom fighter infects this network with a program called a "TapeWorm" forcing the government to shut down the network, thereby destroy its base of power.

Between this and the 1988 worm, it is small wonder that worm programs are getting a bad name. However, the first worm programs were actually designed to facilitate better usage of a network. the first program that could reasonably be called a worm was written in 1971 by Bob Thomas. This program was in response to the needs of air traffic controllers and would help to notify operators of when control of a certain airplane moved from one computer to another. In actuality, the program, called "creeper" only traveled from screen program did not reproduce itself.

In the early 1980s, John Shock and Jan Hepps of Xerox's Palo Alto Center began experimenting with worm programs. (This was the first time that the term worm was actually applied to this sort of code.) The Developed 5 Worms.

Most known Computer Worms are Spread in one of the Following Ways:
  • Files sent as email attachments
  • Via a link to a web or FTP resource
  • Via a link sent in an ICQ or IRC message
  • Via P2P (peer to peer) file sharing networks
  • Some worms are spread as network packets. These directly penetrate the computer memory, and the worm code is then activated.
Difference Between Viruses and Worms

Viruses

A virus is a file that cannot be spread to other computers unless an infected file is replicated and actually sent to the other computer, whereas a worm does just the opposite.

Files such as .com, .exe, or .apk, or a combination of them are corrupted once the virus runs on the system.

Viruses are a lot harder to get off an infected machine.

Their spreading options are much less than that of a worm because viruses only infect files on the machine.


Worm

A worm, after being installed on a system, can replicate itself and spread by using IRC, Outlook, or other applicable mailing programs.
  • A worm typically does not modify any stored programs.
  • As compared to a virus, a worm can be easily removed from the system.
  • They have more spreading options than a virus.
What is Trojan Horse Viruses?

The main objective of this type of malware is to install other applications on the infected computers so it can be controlled from other computers.

Trojans are malicious programs that perform actions that have not been authorized by the user.

These actions can Include:
  • Deleting data 
  • Blocking data
  • Modifying data
  • Copying data
  • Disrupting the performance of computers or computer networks.
The Purpose to create Trojan Viruses?
  1. Crashing the Computer
  2. Data corruption
  3. Formatting disks, destroying all contents
  4. Distributed Denial of Service Attacks
  5. Electronic money theft
  6. Data theft financial implications such as passwords and payment card information
  7. Modification or Deletion of files
  8. Downloading and Installing software, including third-party malware
  9. Keystroke logging
  10. Watching the user's screen
  11. Viewing the user's webcam
  12. Controlling the computer system remotely
  13. System registry modification
Using the infected computer as a proxy for illegal activities and or attacks on other computers.

How you can Know your computer infected with Trojan attacks
  • Browser redirects to unknown pages
  • antivirus is either disabled
  • Malfunctions strange pop-ups 
  • Char messages appear on the victim's systems
  • The ISP complain that the victim's computer is IP scanning
  • The computer shuts down automatically
  • ctrl+alt+del stops workings
  • printer prints documents automatically
Working off some Trojan

The algorithm of the Trojan is as flows:

Search for the root drive.

Navigate to %systemroot%\Windows\System32 on the root drive.

Create the file named "spceshot.dll".

Start dumping the junk data into the above files and its keep increasing size until the drive is full.

Once the drive is full, stop the process.

The Trojan intelligently creates a huge in the Windows\System32 folder with the .dll extension. Since the junk file has the .dll extension it is often ignored by the disk cleanup software. Hence there is no way to recover the hard disk space other than reformatting drive.


Types of Trojans

Remote Access Trojans

This sort of Trojans provides full or partial access and control over the victim system. The server application will be sent to the victim and a client listens on the hacker's system. After the server is started, it establishes the connection with the client through a predefined port. Most of the Trojans are of this kind.

Data Sending Trojans

Using email or a backdoor, this type of Trojan send data such as password, cookies or keystrokes to the hacker's system.

Destructive Trojans

These Trojans are to make destructions such as deleting files, corrupting OS or make the system crash. If the Trojan is not for fun, usually the purpose of such Trojans is to inactivate a security system like an antivirus.

DDoS Attack Trojans

These Trojans make the victim a Zombie to listen for commands sent from a DDoS Server on the internet. There will be numerous infected systems standby for a system since all the systems performs the command simultaneously, a huge amount of legitimate request flood to a target and make the service stop responding.

Proxy Trojans

In order to avoid leaving tracks on the target, a hacker may send the commands or access the resources via another system so that all the records will show the other system and not the hacker's identities. This sort of Trojans is to make a system works as a medium for attacking another system and therefore the Trojan transfers all the commands sent to it the primary target and does not harm the proxy victim.


Security Software Disabler Trojan

This kind of Trojan disables the security system for further attacks.

Example:

Tini: This Trojan listens to port 7777 and provides shell access to the victim's system for the hacker.

ICMD: This application provides shell access, but can accept the password and preferred port.

NetBuss: This Trojan has a GUI for controlling the victim's system. Rather than a serious attack, it's mostly used for fun.

Proxy Server Trojan: This Trojan makes the victim a proxy for attacking another system.

VNC:  Although VNC is not a malicious application however since it is not detected by the Antivirus system it can be used as a means of Trojan horse attack.

Remote by Mail: This Trojan can send and receive commands and data using a series of email. Although compared to a shell session the commands are very limited, however, due to the protocol it uses (SMTP) it can bypass and evade most of the firewall systems.

HTTP Rat: This Trojan sends and receives commands by exchanging series of URPs with a server. Since it uses the HTTP protocol, it is a very dangerous Trojan

How to Protect your Computer with Trojan Attacks

Get an antivirus scanner of the highest quality and, keep it up to date.

Install a firewall to prevent hackers from entering the user system.

Educate users to avoid opening e-mail files, sites, attachments etc.

In Windows, do not open questionable file extensions such as "exe","com", "bat" or "vbs" and ensure

you can view all file extensions. Windows hide long extensions so the file may be "xyz.vbs.png" and, you see only xyz.png.

Protecting against a Trojans Attacks

Click Start, click Run, type regedit in the Open box, and then click OK.

Locate and then click the following entry in the registry.

HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\NoDriveTypeAutorun

Right Click NoDriveTypsAutoRun, and then click Modify.

In the Value Data box, type 0xFF(0x20) to Disable all types of drives. Or, to selectively disable
specific drives, use a different vale as described.

Click Start, point to Settings, click Control Panel, and then double click Network

Click TCP/IP-> Dial-up Adapter, click Properties, and then click the Bindings tab.

Click to clear the File and Printer Sharing check box, click OK, and then click OK.

Restart your computer

(This will Disable the FIle and Printer Sharing component only for the Dial-Up Networking adapter. Local network files sharing or printer sharing is not affected.)

What is Wrapper?

Ethical Hacking Tutorials-What is Viruses, Worms, Trojans ?


The Trojan is combined with another application. This application can be a flash card, flash game, a patch for OS, or even an antivirus.

But actually the file is built of two applications which one of them is the harmless application, and the other one is the Trojan file.

Wrappers

The wrapper is an application which can Join two executable files and produce an application containing both. Most of the times, the Wrapper is used to attack a Trojan file to a small harmless application such as a flash card to deceive to the targeted user and encourage him to execute it.

Some Wrappers are able to make modifications on the Trojan Horse such as compressing it or adding blanks to the end of it and hide it to be detected by the Antivirus.

Some Wrappers Samples

Wrapper COnvert Program One File EXE Maker Yet Another Builder

(Know as YAB and is a very powerful and dangerous application)

Also Read: 




Ethical Hacking Tutorial - Computer Networking

Ethical Hacking Tutorial - Basic Concepts of Networks: What Are Ports And Protocols ?

Computer Networking

Devices 

You Must be Familiar with the Icons that Represent the most common tools seen in the basic Plans.

Ethical Hacking Tutorial - Basic Concepts of Networks: What Are Ports And Protocols ?


Topology

Using these tools, Local Area Network (LAN) can be made. In a LAN, computers can share resources such as hard drives, printer internet connections, and an administrator can control how these resources are shared when a LAN is being designed, any of the following It is also possible to choose Physical Topology:

Bus Topology:

Ethical Hacking Tutorial - Basic Concepts of Networks: What Are Ports And Protocols ?
In Bus Topology, all computers are connected to the same medium of transmission, and each computcan communicate directly with any other.

Ring Topology:
Ethical Hacking Tutorial - Basic Concepts of Networks: What Are Ports And Protocols ?

In the Ring Topology configuration, each computer is connected to the following, and the last one, and each computer can communicate directly with only two adjacent computers.

Star Topology:
Ethical Hacking Tutorial - Basic Concepts of Networks: What Are Ports And Protocols ?

In Star Topology, none of the computers is directly related to others. Instead they are connected to a central point and at that central point the device is responsible for relaying information from computer to computer.

Transmission Control Protocol/Internet Protocol TCP / IP Model

In 1970, TCP / IP was developed by DOD (Defense Department) of the United States and DARPA (Defense Advanced Research Project Agency). TCP / IP was designed as an open standard that any computer can use to connect and exchange simultaneously between them.

TCP / IP model layers

TCP / IP model 4 defines completely independent layers in which it divides the process of communication between the two devices. The layers through which it passes information between the two devices are:

Ethical Hacking Tutorial - Basic Concepts of Networks: What Are Ports And Protocols ?


Application Layer

The application layer is the end user's layer. This is the layer which is in charge of translating data from applications into data which can be sent through the network. 

The basic functions of this Layer
  • Representation
  • Coding
  • Communication Control
  • Application Management
Transport Layers

Transport layer installs, maintains and finishes virtual circuits for information transfer. It provides control mechanism for data flow and allows transmission, and it provides mechanisms to detect errors and improvements.

The information on this layer from the application layer is divided into different segments. The information that comes in the transport layer from the internet layer is sent back to the application layer via ports.

The basic functions of this Layer
  • Reliability
  • Flow Control
  • Correction of False
  • Broadcasting
Internet Layer

This layer divides the segments of the transport layer into packets and sends packets to the network that is making the Internet. This recipient uses the IP, or Internet Protocol address, to determine the location of the device.

It does not ensure reliability in the connection, because it is already taken care of by the transport layer, but it is responsible for choosing the best route between the original device and the receiver device.

Network Access Layers

This layer is in charge of sending information to both LAN level and physical level. It changes all the information that comes from the top layers to the basic information (bits) and direct it to the appropriate location. At this level, the destination of information
Detected by MAC, or Media Access Control, the address of the recipient device.

What is the protocol?

To be able to send information between two devices, both have to speak the same language. This language is called protocol.

Protocols that appear in the Application Layer of the TCP / IP Model

File Transfer Protocol (FTP)
Hypertext Transfer Protocol (HTTP)
Simple Mail Transfer Protocol (SMTP)
Domain Name Service (DNS)
Trivial File Transfer Protocol (TFTTP)

Protocol of Transport Layer

Transport Control Protocol (TCP)
User Datagram Protocol (UDP)

Internet Layer Protocol A

Internet Protocol (IP)

Protocol is often used in the network access layer

Ethernet

Application layer protocol

FTP or File Transfer Protocol is used to transmit files between two devices. It uses TCP to create virtual connections for information control, then creates another connection to use for distribution of data. The most used ports are 20 and 21.

HTTP or Hypertext Transfer Protocol is used to translate the information into web pages. This information is distributed in the way it is used for electronic mail. The port most used is 80.

SMTP or Simple Mail Transfer Protocol is a mail service that is based on the FTP model. It transmits the electronic system between two systems and provides notifications of incoming mail. The most used port is 25.

The DNS or Domain Name Service provides a way to associate a domain name with an IP address. The most used port is 53.

TFTP or Trivial File Transfer Protocols have similar functions to FTP but instead of TCP they use UDP. This gives it more speed, but gives less safety and reliability. The most used port is 69.

Transport layer protocol

Two Protocols can be used by Transport Protocol to distribute information blocks.

TCP or Transmission Control Protocol establishes a logical connection between the final points of the network. It synchronizes and regulates traffic which is known as "Three Way Handshake". In "Three Way Handshake", the original device sends an initial packet called a SYN to the receiving device. The recipient device sends a receipt packet, which is called a SYN / ACK.

The original device then sends a packet called an ACK, which is the acceptance of receipt. At this point, both the original device and the recipient device have installed that there is a connection between the two and the two are ready to send and receive data from each other.

The UDP or User Datagram Protocol is a transport protocol which is not based on connections. In this case, the original equipment receiver sends packets without warning to the device without expecting these packets. It is then up to the recipient device to determine whether the packet will be accepted or not. As a result, the UDP is faster that TCP, but can not guarantee that a packet will be accepted.

Internet Layer Protocol

IP or Internet Protocol acts as a universal protocol to allow any computer to communicate through any network at any time. Like UDP, this connection is unrelated, because it does not establish a connection with a remote computer. Instead, it is known as a best effort service, in which it will be possible to ensure that it works correctly, but its reliability is not guaranteed. 

The Internet Protocol determines the format of packet headers, including the IP address of both the original and the recipient devices.

What is IP address?

A domain name is the web address that you typically type into a web browser. That name identifies one or more IP addresses. For example, the domain name microsoft.com represents nearly a dozen IP addresses. The domain names in the URL are used to identify specific web pages.

For example, in the URL http://www.thehacktech.in the domain name is thehacktech.in.

Each domain name contains a suffix that indicates which top level domain it is (TLD). There is only a limited number of such domains. for example:

.gov      -    Government Agencies
.edu      -    Educational Institutions
.org      -    Organization
.com    -     Commercial Business

Since Internet is based on IP address, not a domain name, every web server requires a Domain Name System (DNS) server so that domain names can be translated into an IP address.

IP addresses are identifiers that are used to differentiate between computers connected to the network and other devices. Each device should have a different IP address, so that there is no problem of wrong identification within the network.

There are 32 bits in the IP address, which are divided into Four 8-bit Octets, which are different from the points. The part of the IP address identifies the network, and the remaining IP addresses identify different computers on the network.

Ethical Hacking Tutorial - Basic Concepts of Networks: What Are Ports And Protocols ?


There are both Public IP Addresses and Private IP Addresses. Private IP addresses are used by private networks, who have no connection to external network. The IP address should not be duplicated within that network, in any personal network, but computers on two different computers - but there may be Duplicated IP addresses in the unwanted private network.

The IP addresses as defined by the AINA, Internet Assigned Number Authority, are available as being available for the private network:

10.0.0.0          to     10.255.255.255
172.16.0.0      to     172.31.255.255
192.168.0.0    to     2.168.255.255

IP addresses are divided into classes, on the basis of which part of the address is used to identify the network and which part is used to identify the personal computer.

Depending on the size allocated to each part, more devices within the network will be allowed, or more networks will be allowed. The current classes.

Ethical Hacking Tutorial - Basic Concepts of Networks: What Are Ports And Protocols ?

Class A: The first bit is always zero, so the squares contain addresses between 0.0.0.0 And 126.255.255.255. Note: Address of 127.x.x.x is reserved for services Loopback or localhost

Class B: The first two bits of the first octet are '10', hence the class contains the addresses Between 128.0.0.0 and 19.1.255.255.255

Class C: The first three bits of the first octet are '110', so this class contains Addresses between 19.0.0.0 and 223.255.255.255.

Class D: The first four bits of the first octet are '1110', so this class contains Addresses between 224.0.0.0 and 23 9.255.255.255. These addresses are reserved Group Multicast implementation.

The remaining addresses are used for use or for potential future Allocation

What is the Port ?

TCP and UDP use ports to exchange information with both applications. A port is an extension of an address, similar to adding an apartment or room number to a street or address. A letter with street address will arrive at the right apartment building, but without the apartment number, it will not be given to the right recipient. The ports work in the same way.

A packet can be delivered to the correct IP address, but without the related port, there is no way to determine which app should work on the packet.

Once defining ports, it is possible for different types of information that are sent to an IP address so that appropriate applications can be sent.

Using ports, one service running on a remote computer can determine what types of information the local client is requesting, can determine the protocol needed to send that information, and many different customers Together they can maintain communication together.

For example, if a local computer attempts to connect to the website www.thehacktech.in whose IP address is 62.80.122.203, with the web server running on port 80, remote computer using the local computer socket address Will connect to:

62.80.122.203:80

In order to maintain standards of standardization among the most used ports, IANA has established that ports ranging from 0 to 1024 should be used for general services.

Remaining Port - through 65535 - is used for dynamic allocation or special Services.

The most used Ports as assigned by IANA are listed here

                -                      -                            -                      Reserved
1-4               -                      -                            -                     Unassigned
5                  -                    rje                            -                    Remote Job Entry
                -                    echo                        -                     Echo
                -                    discard                    -                     Discard
11                -                    systat                      -                    Active Users
13                -                     daytime                 -                   Daytime
15                -                     netstat                   -                  Who is Up or NETSTAT
17                -                     qotd                       -                 Quote of the Day
19                -                     chargen                  -                Character Generator
20                -                     ftp-data                   -                File Transfer 
21                -                     ftp                           -                File Transfer Protocol
22                -                     ssh                          -                SSH Remote Login Protocol
23                -                    telnet                        -               Telnet
25                -                    smtp                        -               Simple Mail Transfer
37                -                    time                         -               Time
39                -                    rlp                            -               Resource Location Protocol
42                -                   nameserver               -               Host Name Server
43                -                   nicname                    -              Who Is
53                -                   domain                      -             Domain Name Server
67                -                   bootps                       -             Bootstrap Protocol Server
68                -                   bootpc                       -             Bootstrap Protocol Client
69                -                    tftp                            -            Trivial File Transfer
70                -                    gopher                       -            Gopher
75                -                      -                              -            Any private dial out service
77                -                      -                               -            Any private RJE service
79                -                    finger                        -             Finger
80                -                    www-http                  -             World Wide Web HTTP
95                -                    supdup                       -             SUPDUP
101              -                    hostname                   -             NIC Host Name Server
102              -                    iso-tsap                      -             ISO-TSAP Class 0
110              -                   pop3                           -             Post Office Protocol - Version 3
113              -                   auth                            -            Authentication Service
117              -                   uucp-path                   -            UUCP Path Service
119              -                   nntp                            -            Network News Transfer Protocol
123              -                   ntp                              -           Network Time Protocol
137              -                   netbios-ns                   -           NETBIOS Name Service
138              -                  netbios-dgm                -           NETBIOS Datagram Service
139              -                  netbios-ssn                  -           NETBIOS Session Service
140-159       -                     -                               -           Unassigned
160-223       -                     -                               -           Reserved


Also Read: Ethical Hacking Tutorials - What is the Wireless Hacking ?

Also Read: Ethical Hacking Tutorials - What is Buffer Overflow Attack ?

Ethical Hacking Tutorials - What is Wireless Hacking ?

Ethical Hacking Tutorials - What is Wireless Hacking ?

What is Wireless ?

allow users to access network resources from nearly any convenient location within their primary networking environment(a home or office). With the increasing saturation of laptop-style computers, this is particularly relevant.

With the emergence of public wireless networks, users can access the internet even outside their normal work environment. Most chain coffee shops, for example, offer their customers a wireless connection to the internet at little or no cost.

Users connected to a wireless network can maintain a nearly constant affiliation with their desired network as they move from place to place.


Initial setup of an infrastruture-based wireless network requires little more than a single access poin. Wired networks, on the other hand, have the additional cost and complexity of actual physical cables being run to numerous locations (which can even be impossible for hard-to-reach location within a building).

Wireless networks can serve a suddenly-increased number of clients with the existing equpment. In a wired network, additional clients would require additional wiring.


Wireless vs Wired Network

Ethical Hacking Tutorials - What is Wireless Hacking ?

A wired network connects devices to the Internet or other network using cable. The most common wired networks use cables connected to Ethernet ports on the network router on one end and to a computer or other device o the cable's opposite end.

Wireless networking is a method by which homes, telecommunication networks and enterprise (business) installations avoid the costly process of introducing cables into a building, or as a connection between various equipment locations.


Wireless telecommunication networks are generally implemented and administered using radio communication. This implementation takes place of the physical level (layer) of the OSI Model network structure.

There are Four Main Types of Wireless Networks


1.) Wireless Local Area Networks(LAN): Links two or more devices using a wireless distribution method, providing a connection through access points to the wider Internet.

2.) Wireless Metropolitan Area Networks(MAN): Connects sererall wireless LANs.

3.) Wireless Wide Area Networks (WAN): Covers large areas such as meighboring towns and cities.

4.) Wireless Personal Area Network(PAN): Interconnects devices in a short span, generally within a person's reach.

Radio Frequency Signal


Although radio frequency is a rate of oscillation, the term "Radio Frequency" or its abreviation "RF" are used as a synonym for radio i.e. to describle the use of wireless communication, as opposed to communication via electric wires

Radio frequency (RF) is any of the electromagnetic wave frequencies that lie in the range extending from around 3 kHz to 300 GHz (Frequency Range)


Radar FM TV Microwaves Infrared




1.) Radio frequency(RF) is any of the electromagnetic wave frequencies (CAT).
2.) That lie in the range around 3 kHz to 300 GHz (Frequency Range)
3.) Like all other electromagnetic waves, they travel at the speed of light.
4.) Naturally occurring radio waves are generated by lightning, or by astronomical objects.

Disadvantages of Radio Frequency Signal


1.) Incontrolled rediation of RF affects pre-adolescent childrens, pregnant women, elderly humans, patients with pace makers, small birds, flora and fauna, small insects etc.
2.) It can be seasily intruded by the hackers and crucial personal official data can be decoded for malicious motives.
3.) Possible Signal Loss weaking of signals.
What is the Difference Between 1G, 2G, 3G, 4G, Mobile Networkds?


1G

Radio signals were transmitted in 'Analogue' form one was not able to do much other than sending text messaging and amking calls. limited network availability

2G

Signal were transmitted in the digital format. Improved the quality of calls Reduced the complexity of data transmission 2G network came in the form of Semi Global Roaming System, which enabled the connectivity all over the world.

3G

Speed of data transmission on a 3G network ranges between 384KBPS to 2MBPS Enables voice and video callin, file transmission, online TV, view high definition videos, play games and much more.

4G

Speed ranging between 100MBPS to 1GBPS


Global Wireless Standards



The IEEE 802 LAN/MAN Standards Committee develops and maintains networking standards and recommended practices for local, metropoliton, and other area networks, using an open and accredited process, and advocates them on a global basis. The most widely used standards are for Ethernet, Bridging and Virtual Bridged LANs Wireless LAN, Wireless PAN, Wireless MAN, Wireless Coexistence, Media Independent Handover Service, and Wireless PAN. An individual Working Group provides the focus for each area.

Local Area Network (LAN)

What is Open System Authentication (OSA) ?

Open System Authentication (OSA) is a process by which a computer can gain access to a wireless network that uses the Wired Equivalent Privacy (WEP) protocol. With OSA, a computer equipped with a wireless modem can access any WEP network and recieve files that are not encrypted.

What is Wireless Threats ?

Wireless threats come in all shapes and sizes, from someone attaching to your WAP (Wireless Access Poin) without authorization, to grabbing packets out of the air and decoding them via a packet sniffer. The airborne nature of WLAN transmission opens your network to intruders and attacks that can come from any direction. WLAN traffic travels over radio waves that the walls of a building cannot completely constrain. Although employees might enjoy working on their laptops from a grassy spot outside the building, intruders and would be hackers can potentially access the network from the parking lot or acress the street using the Pringles contenna.

Wireless Encryption Standards


Wired Equivalent Privacy (WEP)

First 802.11 Security standard easily to hacked due to its 24-bit initialication vector and weak authentication.

How it works

Uses RC4 stream cipher and 64 bit keys. Static master key must be manually entered into each devices.


Wi-Fi Protected Access (WPA)

An interim standard to address major WEP flows, Back wards compatible with WEP devices. It has two models: Personal and Enterprise.

How it works:

Retains use of RC4, but adds longer and 256 bit kyes. Each client gets TKIP Enterprise mode: Stronger authentication via 802.1x and EAP.

Wi-Fi Protected Access (WPA2)

Current standard Newer hardware ensures advanced encryption doesn't affect performance. Also has personal and enterprise modes.

How it works:

Replace RC4 and TKIP with CCMP and AES algorthim for stronger authentication and encryption.

What is SSID

An SSID (Service Set Identifier) is a name that identifies a particular wireless network you are connecting to. Each wireless network in your range will have its own unique name, or SSID. If the wireless network is not broadcasting the SSID, you can use a network analyzer to find it.




What is Access Point 

A Device that ads as the bridge between wireless clients and the wired network Often abbreviated as Access Point

What is Hotspot

An Access Point set up specifically to provide Internet access to users. Hotspot are popular in coffie shops, restaurants, and other other publicly accessible location, and usually do not  require any authentication or offer any encryption. They provide the convenience of free Internet access to attract customers.

What is Captive Portal

In wireless networking, a capture portal is a process running on a access point that can intercept and redirect clients who have associated to a web page where they must agree to terms of service, provide a password, or even purchase access. These are common in hotels, airpots, and other location that offer Internet access but want to charfe a few, restrict it to authorized users, or require the user to accept their AUP.

What is Bandwidth

Network Aandwidth is usually expressed in bits per second (BPS), modern networks typically have speeds measured in the millions of bits per second (megabits per second, or MBPS) or billions of bits per second (gigabits per second, or GBPS).



What is MIMO

Multiple Input or Multiple Output signaling that uses several transceivers and antennae to improve throughput and range of the wireless network. Both access point and clients can use MIMO, though it is most often a feature of access point.

What is War Chalking

Warchalking is the drawing of symbols in public places to advertise onopen Wi-Fi network. Inspired by hobo symbols, the warchalking marks were concieved by a group of friends in June 2002 and publicised by Matt Jones who designed the set of icons and produced a downloadable document containing them.

What is War Driving

War Driving is the act of searching for Wi-Fi wireless networks by a person in a moving vehicle, using a portable computer, smartphone or personal digital assistant (PDA).



Read: Ethical Hacking Tutorials - What is Buffer Overflow ?


Read: Ethical Hacking Tutorials - What is DoS Attack ?


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Ethical Hacking Tutorials - What is Buffer Overflow Attack?

Ethical Hacking Tutorials - What is Buffer Overflow Attack?

What is Buffer Overflow Attack?

Buffer Overflow have been the most common form of security vulnerability in the last ten years. Moreover buffer ouverflow vulnerabilities domain at in the area of remote network penetration vulnerabilities, where an anonymous Internet user seeks to gain partial or total control of a host. Because these kinds of attacks enable anyone to take total control of a host, they reppresent one of the most serious classes security threats.



Buffer Overflow attacks is the form a substantial partion of all. Security attacks simply because buffer overflow vulnerabilities particularly dominate in the class of remote penetration attacks because a buffer overflow vulnerability presents the attacker with exactly what they need the ability to inject and execute attack code.

The injected attack code runs with the privileges of the vulnerable program and allows the attacker to bootstrap whatever other functionality is needed to control the host computer.

The overall goal of a buffer overflow attack is to subvert the function of a privileged program.

To achieve this goal, the attacker must achieve two sub goal

1. Arrange for suitable code to be available in the program's address space.
2. Get the program to jump to that code, with suitabe parameters loaded into register and memory.

A Buffer contains data that is stored for a short amount if time, typically in the computer's memory(RAM). The purpose of a buffer is to hold data right before it is used. 

For example, When you Download an audio or vidoes file from the Internet. it may load the first 20% if it into a buffer and then begin to play. While the clip pays back, the computer continually downloads the rest of the clip and stores it in the buffer. Because the clip is being played from the buffer, not directly from the Internet, there is network congestion.


A data buffer (or just buffer) is a region of a physical memory strage used to temporarily store data while it is being moved one place to another.

What is Temporary Data Storage ?

A Temporary Storage Area, usually in RAM. The purpose of most buffers is to act as a holding area, enabling the CPU to manipulate data before transferring it to a device.

Because the processes of reading and writing data to a disk are relatively slow, many programs keep track of data changes in a buffer and then copy the buffer to a disk . For example, word processors employ a buffer to keep track of changes to files. Then when you save the file, the word proccessor updates the disk file with the contents of the buffer. This is much more efficient than accessing the file on the disk each time you make a change to the file.

Note: that because your changes are initially stored in a buffer, not on the disk, all of them will be lost if the computer fials during an editing session


For this reason, it is a goal idea to save your file periodically. Most word processors automatically save files at relular intervals.

Heap Area in Programming Languages 

In certain programming languages including C and Pascal, a heap is an area of pre reverved computer main storage (mamory)  that a program process can use to store data in some variable amount that won't be known unitl the program is running.


For example, a program may accept different amoutns of input from one or more users for processing and then do the proccessing on all the input data at once. Having a certain amount of heap storage already abtained from the operating system makes it easier for the precess to manage storage and is generally faster than aking the operating system for storage every time it's needed. 

The process manages its allocated heap by requesting a "chunk" of the head (called head block) when needed, returning the blocks when no longer needed, and doing occasional "garbage collecting," which makes blocks available that are no longer being used and also reorganize the available space in the heap so that it isn't being wasted in small unusel pieces.

The term is apparently inspired by another term, Stack. A stack is similar to a heap except that the blocks are taken out of storage in a certain order and returned in the same vay. Int Pascal, a sub head is a portion

Buffer Overflow Attack

Ethical Hacking Tutorials - What is Buffer Overflow Attack?


A heap is an area of prereserved computer main storage (memory) that a program process can use to store data in some variable amount that won't be known until the program is running.
The stack is a pleace in the computer memory where all the variable that are declared and initialized before runtime are stored. The data are declared and initialized before runtime are stored. The data added or removed is in last-in-first-out (LIFO) manner.

Mainly local variable are stored in stack. After the program execution the stored data is automatically deleted and this for temporary storage. The memory block in stack has fixed size. If there is not enugh memory on the stack to handle the memory being assigned to it, a Stack Overflow occurs.



Also See: Ethical Hacking Tutorials - What is DoS Attack?

Also See: Ethical Hacking Tutorials - What is Session Hijacking?


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