A computer virus is a small program that spreads from one computer to another and interferes with computer operation. Viruses can spread through email attachments, downloads, shared files, and more. Infected computers may experience slow performance, crashing, missing files, and unusual error messages. To protect computers, people should install antivirus software, update security programs, use firewalls and pop-up blockers, and backup important files. Antivirus programs detect and remove known viruses, while online scanning services can also help identify infected files.

1. Prepared For
Salmeen Rahman
Prepared By
MD ISMAIL HOSSAIN
AMINUR
BBA-A
#15102047
Computer virus
Topic:

2. Definition of virus:
A computer virus
is a small
software
program that
spreads from one
computer to
another, and
interferes with
computer
operation.

3. Types of virus
 Resident Viruses
 Worms viruses
 Direct Action Viruses
 Overwrite Viruses
 Boot Virus
 Macro Virus
 Directory Virus
 Polymorphic Virus
 Network Virus
 FAT Virus

4. How to spread virus:
Through attachments
Through email messages
Through funny images, greeting
cards
Through audio and video files.
Through downloads on the Internet
And the Common methods for
spreading viruses include floppy disks,
FTP file transfers, and copying files
between shared network drives.

5. Computer Virus Symptoms
1.Hardware Troubles
2.Slow Performance
3.Slow Startup
4.Crashing
5.Missing files
6.Unusual Error Messages

6. How I can help protect my computer from viruses
1.Install an update antivirus program:
2.Don't open email messages from
unfamiliar senders, or email
attachments that you don't recognize
3.Use a pop-up blocker with your
browser
4. Keep Windows updated
5. Use a firewall
6. Use your browser's privacy settings
7. Clear your Internet cache and your
browsing history
8. Scan any email or files downloaded
from the Internet before you open them

7. Antivirus software
Many users install
antivirus software
that can detect and
eliminate known
viruses when the
computer attempts
to download or run
the executable

8. Recovery strategies and methods
One can also reduce the
damage done by viruses
by making regular
backups of data on
different media, that are
either kept unconnected
to the system read-only or
not accessible for other
reasons, such as using
different file systems. This
way, if data is lost through
a virus, one can start again
using the backup

9. Virus removal
Many websites run by antivirus software
companies provide free online virus scanning,
with limited cleaning facilities . Some
websites—like Google subsidiary
VirusTotal.com—allow users to upload one or
more suspicious files to be scanned and
checked by one or more antivirus programs in
one operation.