Computer Security

 Computer Security 

If you want a computer to be perfectly secure, you could fill it with concrete and dump it in the ocean. This would protect any information on the computer from inappropriate use. Unfortunately, the compute would completely unusable. So you probably don't do short. Since you want to both use the computer and keep it safe, you should practice good computer security. Computer security allows you to use the computer while keeping it safe from threats. 

Computer security can defined as controls that are put in place to provide confidently integrity, and available for all components of computer system. These components include data, software, hardware and filmware. 

What is Computer Virus :- A computer virus is a malicious program written to alter the way a computer operates, without the permission or knowledge of the user. A virus replicates itself i.e. ir makes copies itself. A virus attaches itself to a program or file and copies itself to other files. 

A virus may just display a funny message or may do something really damaging like wiping out the entire hard disk content. As the computer virus is a program, the amount of damage a virus would inflict depend on damage the virus writer want it to do. 

There are two types of ways in viruses operates, as soon as they land on a new devices they begin replicating while the second  type plays dead until a particular trigger makes malicious code to executed.

The History of Computer Virus :-  Robert Thomas, as engineer at BBN Technologies developed the first known computer virus in the year 1971. The first virus was christened as the "Creeper" virus and the experimental program carried out by Thomas infected mainframes on ARPANET. The teletyped message displayed on the screens read, "I'm the creeper. Catch me if you can."

But the original wild computer virus probably the first one to be tracked down in the history of computer viruses was "ELK Cloner". The ELK Cloner infected Apple II operating system through floppy disks.

It was Fred Cohen, who coined the term "computer virus" and it was after a year in 1983. The term came into being when he attempted to write an academic paper titled "Computer Viruses - Theory and Experiments" detailing about the malicious program in his work. 

Types Of Computer Viruses :- A computer virus is one type of malware that inserts its virus code to multiply itself by alter the program and application. The computer gets infected through through the replications of malicious code.

Computer viruses come in different form to infect the system in different ways. Some of the most common viruses are:

• Boot Sector Virus :- This type of  virus infect the master boot and it is challenging and a complex task to remove this, virus and often requires the system to be a formatted. Mostly it spread through removable media.
• Direct Action Virus :- This is also called non-resident virus, it gets installed or stays hidden in the computer memory. it stays attached to the specific types of files that it infect. It does not affect the user experience and system's performance.
• Resident Virus :-  Unlike direct action viruses, resident viruses get installed on the computer.It is difficult to identify the virus and is even difficult to remove the virus.
• Multipartile Virus :- This type of virus spread through multiple ways. It infects both the boot sector and executable files at some time. 
• Space Filler Virus :- This is also called "Cavity Virus" This is called so as they fill up the empty spaces between the code and hence does not cause any damage to the file .
• File Infector:- Few file infector viruses come attached with program files such as .com or .exe file. Some file infector viruses infect any program for which execution is requested, including .sys, .ovl, .prg, .mnu files.
• Macro Virus:- The macro viruses particularly target macro language commands in applications like Microsoft word. The some is implied on other program too.