what is virus in computer ?

[RITESH KAKKAR]

Hello,

Why people make virus and what is do its type?

 

[BradtheRad]

Today there are malwares that can encrypt data on your hard drive, then demand a money payment within a certain amount of time, in order to get your data back.

With the internet becoming popular, there are also virus programs which hijack your browser, directing you to advertising and business websites.

There are fake anti-virus programs, which themselves contain a virus. They insist that you buy a subscription to get rid of the virus which they put on your computer.

Money has become a prime reason for the criminal-minded to create a virus.

In earlier days, a virus might display a prank message, or cause a computer crash. These were a nuisance, causing loss of work. There were fewer virus programs, and fewer avenues to spread them.

 

[hobbyckts]

Virus or Malware were created to crash the system and destroy the data completely or partially

 

[RITESH KAKKAR]

Hello,
how kaspersky make antivirus doctor?

 

[ads-ee]

Hello,
how kaspersky make antivirus doctor?

In a literal sense, they make the tool using a large team of software engineers and virus experts to develop the tool.

In a more general sense of how the tools work (as I think that is what you are really asking)...

Many antivirus tools read signatures (small sequences of instructions) in a file that do certain virus like things, e.g. erasing the MBR table, attaching itself to other .exe files, etc.

Some of the tools use other methods like heuristic algorithms (self learning) to improve performance, this doesn't necessarily mean better.