A computer virus is a program that installs itself and runs without permission on an infected computer. There are different types of viruses like email viruses, trojan horses, and worms. Viruses can spread through email attachments, websites, networks, software, and removable drives. Symptoms of a virus include slow performance, unexpected program/file changes, browser issues, and unauthorized emails sent from the infected device. People are advised to use antivirus software, practice safe browsing/email habits, keep systems updated, and use firewalls to protect against viruses. Popular antivirus programs are listed that can help keep computers secure.

2. What is Computer
Virus?
A computer virus is a program or piece of code
that is loaded onto your computer without your
knowledge and runs against your wishes. Viruses
can also replicate themselves. All computer
viruses are man-made.

3. Different types of
Computer VirusesE-mail viruses: An e-
mail virus travels as an
attachment to e-mail
messages, and usually
replicates itself by
automatically mailing
itself to dozens of
people in the victim's e-
mail address book.
Trojan horses: A Trojan
horse is simply a computer
program. The program
claims to do one thing (it
may claim to be a game)
but instead does damage
when you run it (it may
erase your hard disk).
Trojan horses have no way
to replicate automatically.
Worms: A worm is a small piece of software that uses computer networks and security
holes to replicate itself. A copy of the worm scans the network for another machine that
has a specific security hole. It copies itself to the new machine using the security hole,
and then starts replicating from there, as well.

4. Symptoms of Computer
Virus
 Your Desktop looks different.
 Your Home Page changed.
 Everything is Sloooooooooow.
 Programs or Files Appear or disappear without Your
Knowledge.
 The Browser may not respond, Close Unexpectedly, or
Randomly Redirect.
 Bizarre Error Messages.
 Unexpected Freezing.
 Your contacts receive Emails from your account that you
didn’t send.

5. How does Computer
Virus spread
 Email attachments.
 Rogue Websites.
 Networks.
 Infected Software.
 Hackers.
 Fake Anti Virus Software.
 Friends and Relatives.
 From Mobile Devices.
 From infected Pen drives.

6. Some ways to protect
your computer from
viruses Install an antivirus program.
 Don't open email messages from unfamiliar
senders, or email attachments that you don't
recognize.
 Use a pop-up blocker with your browser.
 Keep Windows updated.
 Use your browser's privacy settings.
 Use a firewall.
 Clear your Internet cache and your browsing

7. Some famous Antivirus Software's
to keep your computer
SAFE & SECURE
Kaspersky Anti-Virus
Norton Anti Virus
F-Secure Anti-Virus
Bull Guard Antivirus
AVG Anti-Virus
Panda Antivirus Pro
G Data Anti Virus
McAfee Antivirus Plus
Avast! Pro Antivirus
Quick Heal Antivirus