welcome to What is a Computer Virus
What is a Computer Virus ? :: A Computer Virus is a program or programming codes and set of codes which are composed, designed and written by software Developers or programming engineer to hurt or infect other computers locally or in PC systems network. They are capable of contaminating and infecting other PC by duplicating or reproducing itself as a natural biological virus. A portion of them are innocuous while different viruses can harm or damage computer system seriously and can harm computer client and users to an extent. Computer viruses can replicate itself and infect different computer shockingly and without any information to computer user or client, they can hide themselves and attack aggressively when comes in contact to "HOST“
They are spread by utilizing infected or contaminated media when these infected media is taken to uninfected computer it get infected or by downloading Documents, videos, pictures, and content from the internet which contains malicious programs. The Known First computer virus was developed by two Pakistani Brothers from Lahore in 1986 and named it as 'BRAIN VIRUS'
Different Types Of Computer Viruses
The computer viruses can be classified in Following types :: System Virus File Viruses Boot Sector or Boot Record Viruses
System Virus
System Viruses are computer program or software codes which resides and lives inside the system area of the hard disk or any other media which contains MBR (Master Boot Record),they infects the boot area of system, and various other locations of the Operating systems. They mainly try to infect or contaminate boot files namely command.com,Io.sys and Msdos.sys these are the system files which carries out the boot process of a working operating system.
They are computer program which resides inside the system area of the hard disk or any other media which contains MBR (Master Boot Record),they infects the boot area of system, and various other locations of the Operating systems. They mainly try to infect boot files namely command.com,Io.sys and Msdos.sys these are the system files which carries out the boot process of an operating system. They basically try to infect the input and output functions of computer systems. They even can remain or dwell in the system area & can do its work of contaminating and infecting other system records which are critical and cruical to run the boot procedure of computer system
Trojan Viruses
Trojan Horses is a malicious program designed, developed, planned and created to harm the computer system. The codes are customized such that when it interacts with some other program or documents it changes them into Trojan virus. They control and perform the task of controlling and manipulating the critical files of working system it infect and harms File Allocation Table of HARD DISK DRIVES which contains important and crucial data of Computer system [PC].
Macro Viruses These are a tiny program which is composed inside information files . Which can be attached to any files, for example, text or even graphics, for example, pictures, images or videos which are not harmful as different other types of viruses. These types of viruses don't infect program files, for example, .EXE or.COM they contaminate application program, for example, word or speed sheets. They are the most widely recognized viruses seen nowadays. They are created to harm application program. Regular scanning of hard disk must be done, checking and scanning of viruses from removable disk such as DVD CD and pen drives or external computer hard disk must be done periodically.
Worms
A worm is a bit of code which is customized such that it replicates itself when interacts with other different computers in the network. Worm more often that not harm computers when connected to each other via networking. These type of viruses which are attached to files or programs and harm or manipulate the system files which are available in your computer systems.
File Viruses
These programs infect executable files and records such as .EXE and.COM. They at times change the extension of the file and make them useless. These viruses are attached to the start or the end of the executable files and records, they don't harm data files and do not make any manipulation Inside the files and usually, change the functionality and performance of the executable files. They change the programmed code of the executable files and documents. which are written and composed for a specific, particular and special task to perform and hence abnormal set of instruction is executed when someone runs them
Boot Sector or Boot Record Viruses
The Boot sector or Boot Record Viruses are additionally called as "PARTITION VIRUS“. The computer starts from the boot area of the hard disk which is 0, 0.1 sector of computer hard disk drive [HDD]. In this sector, vital boot records are stacked which causes a computer to start or boot the operating system. This code in boot sector stacks in partition table and PC hard drives have partition table which is a basic part which loads the working operating system.
As they stay active in memory, therefore, they can be called as 'MEMORY RESIDENCE VIRUS' these programs or codes contaminate clean startup records and executable files to wreck the boot procedure of operating system and even can erase the information present in the computer hard disk.
Removal and Precautions Taken Against Computer Viruses? They have become smarter these days, and even can make a fool of good antivirus software and are developed by the programmers who want to harm the computer system. They reside in the memory and do all the functions they have been developed for. They tend to hide themselves in such a fashion that it is very difficult to eliminate them after infection Never ever try to open or copy data from an unknown source before doing so scan it with good antivirus program which is updated and can eliminate or remove any malicious program or virus-like activity from your computer system.
One Should always use legal antivirus Software. Regular Update of such antivirus must be done periodically. Never try to open or download from unknown Websites or copy any files, documents, images, videos and content from infected USB Drives and CD's or DVD's. Never visit pornographic websites as they contain malicious program which can hurt or damage system files or operating system. One must not download pirated software which may contain malicious program. You must scan any USB medium before using. Always beware of phishing attacks generally happens when clicked on websites which are not authenticated.
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