Virus is a program written to enter to your computer and damage/alter your files/data. One of the biggest fears of having computers are viruses.Viruses are malicious programs designed entirely for destruction and havoc. Viruses are created by people who either know a lot about programming or know a lot about computers.

The virus is distributed through shareware, pirated software, e-mail, or other​ various means. Once the virus infects someone’s​ computer it will either start infecting other data, overwriting data, or corrupting software.

A computer Virus is more dangerous than a computer worm as it makes changes or deletes your files while worms only replicates itself with out making changes to your files/data.

The memory-resident virus first attaches itself to memory and then infects the computer. The virus can also be non-memory resident which means a  program must be run in order to infect the computer

Resident Virus is file infector

Resident viruses are the other primary type of file infectors. Unlike direct action viruses, they install themselves on a computer. It allows them to work even when the original source of the infection has been eradicated. As such, experts consider them to be more dangerous than their direct action cousin.

Depending on the programming of the virus, they can be tricky to spot and even trickier to remove. You can split resident viruses into two areas; fast infectors and slow infectors. Fast infectors cause as much damage as quickly as possible and are thus easier to spot; slow infectors are harder to recognize because their symptoms develop slowly.

In a worst-case scenario, they can even attach themselves to your anti-virus software, infecting every file the software scans. You often need a unique tool—such as an operating system patch—for their total removal.

Resident viruses live in your RAM memory. It can interfere with normal system operation which can lead to the corruption of files and programs. The most popular examples of resident viruses are CMJ, Meve, MrKlunky, and Randex.

A few computer virus symptoms are:

  • Computer and/or internet suddenly slower
  • Computer behaves weird
  • PC freezes and crashes a lot
  • Unusual error messages appear
  • Files have been automatically deleted or added
  • Unwanted advertisements appear
  • Emails have been sent from your account to your contacts (which you know you didn’t sent)
  • Sudden hardware problems (e.g., display acting weird)
  • Antivirus software and/or its shields are turned off automatically
  • PC automatically restarts (reboots) by itself

Computer Virus Protection

  •  Use a highly-regarded antivirus suite
  • even free online virus scanner and removal tools can be used with caution
  • Don’t open emails from unrecognized sources
  • Don’t install software from random websites.