Computer Virus Types And Effect

Computer Virus

Computer Virus Types And Effect-:VIRUS (Vital Information Resources Under Siege) Computer viruses are perverse software or small programs that can negatively affect the computer. It obtains control of a PC and direct it perform unusual and after and destructive actions. Viruses are copied itself and attached itself to other programs which further is spread the infection. The virus can affect or attack any part of the computer software such as the boot block , operating system , system areas , files and application program.

Malware is a category of computer infection. Viruses are the most familiar infection. This infection type is what is name implies, spying on you and your computer activity. Adware is fed by spyware. Spyware sends message back to the developer and then Adware is sent to your computer creating pop up. Worms are familiar to some as a form of infection also. This type eats your data until the drive is empty. There is an infection called a boat which event through it has a small name its effect is deadly this type of malware communicates with the source developer of the bot and send information from your computer . The information being send could be your email address on your ID and password.

Computer virus is a small block of coded instruction that obtains control of a PC’s CPU and direct it to perform unusual and often destructive action.

 How Computers Virus Spread?

Computer viruses move from computer to computer by attaching themselves to file or boot record of disc and biscuits these days it is not uncommon 2 find them in email attachment and other program that can be downloaded from the internet.

A virus is a relatively passive agent that can travel from 15 to another on the same computer if the infected file is executed from computer memory to a file on this on a disc that is carried from one computer to another some companies prohibited property drive there by preventing users from copy information on to their computers on email attachment executable file and over a modem of network connection.

Types of Computer Virus

  1. Trojan Virus 
  2. Worms Virus 
  3. Boot sector Virus 
  4. Macro Virus 
  5. Memory Resident Viruses 
  6. Root kit Virus 
  7. Polymorphic Virus 
  8. Logic Bombs / Time Bombs 
  9. File system Virus
  10. FAT Virus 
  11. Overwrite Virus 
  12. Direct action Virus
  13. Resident Virus 
  14. Web Scripting Virus 
  15. Multipartite Virus 

Trojan Virus

Trojan Computer Virus

A Trojan, or Trojan Horse, is a non-self-replicating type of malware which appears to perform a desirable function but instead facilitates unauthorised access to the users computer system. Trojans do not attempt to inject themselves into other file like a computer virus. Trojan horses may still information, or harm their host computer systems. Trojans may use drive- by downloads or install via online games or internet- driven applications in order to reach target computers. Unlike viruses, Trojan horses do not replicate themselves.e.g. Beast , Sub7.Zeus , Zero access Rootkit, etc .

How Trojans Virus Spread? 

Trojan horses generally are spread through email and exchange of disc from information between computer . Warm code also spread trojan horses.

Damage Caused by Trojan Horses?

The damage that Trojan horse cause is much the same as water virus most of the time the user or an aware of the damage it is causing because of the Trojan horse masking effect.

Worms Virus

Worm Virus

A worm is also a program that makes a available the distribution of copies of itself. Worm virus will spread from one disc drive to another or by copying itself use using email or another transport mechanism. The worm can also damage the computer system and affect the security of the computer system. It appears in your computer through exploitation of a system will downloading and infected e-mail.e.g. Bagle , I Love You , Morris , Nimda , etc.

How Worms Spread ?

Worms are autonomous agents capable of propagating themselves without the use of another program or intervention or action by a user . Worms are found primarily on computers that are capable of multitasking and are connected by a network.

Damage that Worms Can Cause?

Most worms disrupt services and create system management problems. Some Worms scan for password and other loopholes and then send the information back to the attackers.In some cases Worms can install Trojan horses or viruses that causes damage to the system.

Boot Sector Virus

Boot Sector Virus

Is also called Master Boot Sector virus or Master Boot Record virus this type of virus affect the boot sector of a hard disc.

Boot sector virus enter the first part of the hard disk. This part is used by the computer system to read and start. Normally, this virus will attack the entire boot sector and damage it. Such type of virus normally spread through floppy disks.e.g. Polyboot.B, AntiEXE, etc.

Macro Virus

Macro Virus

It infects files that are created using certain application or program that contain macros, like .doc , .xls , .ppt , etc .

Macro Viruses aur such type of viruses that uses other application of macro programming language to distribute them. Macro virus infect the Microsoft documents such as MS word or MS Excel. Macro virus spread with in this Microsoft document and damage them.e.g. Melissa.A.

Memory Resident Virus

Memory Resident Virus

It fix themselves into the system’s memory and get activated whenever the OS run and infect all the files that are then opened. It hides in the RAM and stays there even after the malicious code is executed.

Memory resident virus stays inside the computer volatile memory such as RAM. They are initiated from a virus which runs on the computer and remained inside the memory  after it’s initiating program closes.e.g. Randex , Meve , etc.

Root kit Virus

Root Kit Virus

A Root Kit Virus is a different type of virus which cannot be detected easily and appears if someone gain control of a computer system. Such viruses are usually installed by trojans and are normally hidden inside and operating system files.

Poly Morphic Virus

Poly Morphic Virus

It encrypts or encodes itself in an encrypted way, every time it infects a system. This virus can goes on to create a large number of copies.

Such type of virus alter its own code when they in affect another computer they do this because they want to try and avoid detection by anti-virus program. e.g.Elkern, Tuareg, etc.

Logic Bomb/Time Bomb Virus

Logic Bomb Virus

These are viruses which are program to start at a specific date or when a specific event occurs. Some example or a virus which delete your photos on Halloween, or a virus which delete a database table if a certain employee gets fired.

File System Virus

File System Virus

It is also called Cluster Virus or Directory Virus. It infects the directory of your computer by changing the part that indicate the location of a file. e.g. Dir-2 virus.

FAT Virus

FAT Virus

It is used to store all the information about the location of files, unusable space, etc.e.g. Link Virus, etc.

Overwrite Virus

Over Write Virus

It delete the information contained in the file that it infects, rendering them partially or totally useless, once they have been infected.e.g. Way , Trj.Reboot, Trivial.88.D, etc.

Direct action Virus

Direct Action Virus

It comes into action when the file containing the virus is educated. It infects file in the folder that are specified in the AUTOEXESC. bat file path. e.g.Vienna virus .

Resident Virus

Resisdent Virus

It fixes themselves into the system’s memory and get activated whenever the OS run and infect all the files that are then opened . It hides in the RAM and stays there even after the malicious code is executed. e.g. Randex, Meve, etc.

Web Scripting Virus

Web Scripting Virus

Many website execute complex code in order to provide interesting content. These sites are sometime created with purposely infected code.e.g. JS Foresight .

Multipartite Virus

Multipartite Virus

It may spread in multiple ways such as the operating system installed or the existence of certain files . e.g.Flip.

Effect of Computer Virus

There are many different effect that viruses can have on your computer depending on the types of virus some virus can.

  1. Monitor what you are doing.
  2. Slow down your computer performance.
  3. Destroy all data on your local disk.
  4. Effect on computer network and the connection to internet.
  5. Increase or decrease memory size.
  6. Display different types of error message.
  7. Decrease partition size.
  8. Alter PC setting.
  9. Display arrays of annoying advertising.
  10. Extend boot Times.
  11. Create more than one partition.

Securing PC

Securing PC

Follow these steps to secure your PC from Cyber Crime :-

  • Only use trusted sites when providing your personal information:- A good rule of thumb is to check the URL if the site include “https://,” then it’s a secure site.If URL includes “https://,”- note the missing “s”- avoid entering sensitive information like your credit card data or Social Security number .
  • Don’t open email attachment or click link in the email from unknown sources:- One of the most common way people are attacked is through email hidden as being sent by someone you trust.
  • Always keep your device updated:- Software update contain important patches to fix security issues cyber attacks thrive on our data device because they don’t have the most current security software.
  • Backup your file regularly:- To prevent cyber security attacks if you need to wipe your device clean due to Cyber attack it will help to you have your file is stored in a safe separate place.
  • Enable your firewall:-  A firewall act as a barrier between your computer or network and the internet if effectively closes the computer ports that prevent communication with your device this protect your computer by stopping threads from entering the system and its trading between devices if your computer course are open anything coming into them could be procedure this is bad if it’s malicious programs and bhaiya hacker while it’s possible to close sports manually a firewall act as a simple defence to close sports the fire wall will help open the ports only to trusted application and external devices on and as needed basis.
  • Adjust your browser setting:- Most browser have option that enable you to adjust the level of privacy and security while you browse this can help lower the risk of malware infection reaching your computer and malvisors malicious hackers attacking your device some browser even enable you to tell website not to track your movement by blocking cookies however many of the option are disabled by default so you could unwillingly by be exposing for more than you need to each time you Bros while using this browser Chrome Firefox Safari and you can add and additional layer of protection by installing and anti tracking browser extension like disconnect or you block origin.
  • Install antivirus and spyware software:- Any machine connected to the internet is inherently vulnerable to virus and other threats included malware ran somewhere and Trojan attack anti-virus software is not a completely full proof option but it can definitely help is 5 year reserve is Pacific types of malware they that is designed to security in fact or computer if then side in the system gather information and send it to or third party the information typically of a sensitive nature such as credential or banking information this can ultimately lead to identity thift multi billion industry if its 5 where has found its way on to your computer then it’s very possible you can remove it there are turn off option for spyware removal including many free offering and some paid single use tool.

Some popular Antivirus Software:-

  1. Avast 
  2. K7
  3. Trend Micro 
  4. Symantec
  5. McAfee
  6. Avg 
  7. Kaspersky
  8. Quick Heal 
  9. Nortan
  • Password protect your software and blocks your device:- Most web connected software that you can install on your system require login credential the most important thing there is not to use the same password across all application this makes it far to easy for someone to hack into all of your account and possibly still your identity if your device or lost or stolen they can grant other access to sensitive data hackers can even turn your own hardware into a liabilities so you can secure your device with strong security password use upper case lower case and numerical character for a more secure password fix something unexpected that makes and to you but nobody else that will make it nearly impossible to guess.
  • Encrypt your data:- Whether your computer houses your life work or a load of file with sentimental value like photos and videos it’s likely worth protecting that information one way to ensure it does not fall into this wrong hand is to encrypt your data encrypted data will require resources to script descript it this alone might be enough to data from pursuing action.
  • Use of VPN:- Virtual Private Network (VPN) is an excellent way to step up your security especially when browsing online while using a VPN all of your interest traffic is encrypted and tunnelled through and intermediate server in a separate location this makes your IP replacing it with a different one so that your ISP can no longer monitor your activity.
  • Digital Signature :- it is an electronic form of a signature that can be used to authenticate the Identity of the centre of a message or the signal of a document, and also insure that the original content of the message or document that has been sent is unchanged.

Some common viruses are tabulated below:-

1982Elk Cloner
1988The Morris Internet Worm
2000I Love You
2001Code Red
2003SQL Slammer
2014Generic PUP
2014Net Worm

Note:-  Brain was the first PC  boot sector virus created in 1986.

creeper was the first computer virus created in 1971.

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About the author

Pooja Rastogi

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