Computer has become indisputable part of our life. We can't imagine our life without computer in present scenario. Imagine ! What will happen when your computers stops working . Really it will cause a lot of problems along with financial losses too!
The main threat to our computer is "computer virus".
A computer virus is a computer program that makes a copy of itself and multiplies at very high rate. The term virus is also used for other malware. Computer virus mainly propagates through USB drive, CD , DVD or floppy disk .
A computer virus can completely cease the computer and network. Some programmers create these programs intentionally so that they can hack other computers and networks.
Strategies in which virus spreads :
For multiplication only if it is allowed to execute code and write memory. For this viruses attach themselves to executable files .
We mainly divide viruses into two categories. First is non resident virus and other is non resident virus.
Nonresident viruses seek for other hosts that can be infected immediately. First of all they try to infect host and later the control is transferred to application programs.
On the other hand resident viruses work in a different manner. First of all they get loaded into memory on execution and later the control is transferred to the host programs. It remains active in the background and keep on infecting the hosts.
How computer viruses mask themselves?
Most of the time ,we even don't know where the virus is exactly? In fact viruses use various deceptive methods to hide itself from users. The solution for computer virus removal is only a use of anti virus .
Some viruses on Ms-dos operating systems ensure that the last modified date of host file remains the same , whenever virus infects it . Now this method employed by virus can be easily detected by anti viruses.
Some viruses infects a file by writing programs on unused space of executable file . These are termed as "cavity viruses ". " Chernobyl virus" is one of the example of this sort of viruses.
Also most of the viruses are programmed in " .Exe " file. So users of windows operating system are more prone to these virus attack. Thus Linux is comparatively safer operating system .
Computer viruses are mainly programmed due to various bugs in operating systems and software.
The best way for computer virus removal , is use of a branded and good anti virus. We should also prevent ourselves from transferring and downloading any data from unreliable sources.