A computer virus is a program that can replicate itself is usually designed to manipulate, damage, or delete data on an infected computer. Viruses have a better chance of spreading themselves when they manage to attack the operating system's file system. A virus makes unauthorized and therefore unwanted changes to the operating system, even though they may not be harmful.
For virus detection and removal, there are plenty of antivirus programs that can help. Unfortunately, it often happens that the user introduces a virus into the computer himself, due to his ignorance. Trojan horses, adware, spyware and other malicious programs are sometimes mistaken for viruses.
The first academic paper on the subject of computer viruses was published in 1949. At that time, the term 'computer virus? did not exist and the paper was called and the author of the paper, John von Neuman, described how a program could be designed to reproduce itself.
The first computer virus to appear on the open network (not in laboratories or on test computers) was Elk Cloner. It was written by Richard Skrenta in 1981. It spread via floppy disks and did no damage, only spreading itself further and displaying a poem after the 50th execution.
How to remove the virus: either with an antivirus program or with a system restore, which most modern operating systems provide. Some viruses can prevent system recovery and are capable of blocking other important system functions. In such cases, it may help to reboot the computer into so-called safe mode, which is usually not affected by the virus. Reinstalling the entire operating system can also help in an emergency.
How to defend against a virus that attacks your site via FTP? You can find the procedure here.
