about computer virus in short

1. Presented by- Joydip

2. What is computer virus?
 A Computer virus is a malicious software program
loaded onto a user’s knowledge and performs
malicious actions . it can self replicate, inserting itself
onto other programs or files ,infecting them in the
process .not all computer viruses are destructive tough.

3. Type of computer virus :
 Direct Action Virus. ...
 Browser Hijacker. ...
 Overwrite Virus. ...
 Web Scripting Virus. ...
 Boot Sector Virus. ...
 Macro Virus.
 Directory Virus
 Polymorphic Virus
 File Infector Virus
 Encrypted Virus

4. Direct Action Virus. ...
 Direct action viruses attack certain types of files,
typically .exe and .com files. The main purpose of this
virus is to replicate and infect files in folders. On the
lighter note, they do not typically delete files or affect
PC performance and speed. It can be easily removed by
antivirus programs

5. Browser Hijacker. ...
 This type of virus infects your web browser in which it
will bring you to different websites. Typically, if you
key in a domain name in the internet address bar, the
browser hijacker will open multiple fake websites that
may harm your computer. On the other hand, most
trusted browsers have built-in features to block them
ahead.

6. Overwrite Virus. ...
 From the name itself, this virus overwrites the content
of a file, losing the original content. It infects folders,
files, and even programs. To delete this virus, you also
need to get rid of your file. Thus, it is important to
back up your data.

7. Web Scripting Virus.
 This virus lives in certain links, ads, image placement,
videos, and layout of a website. These may carry
malicious codes in which when you click, the viruses
will be automatically downloaded or will direct you to
malicious websites.

8. Boot Sector Virus.
 Boot sector viruses affect floppy disks. They came to
existence when floppy disks are important in booting a
computer. Although they are not very common today,
it is still causing other computer units, especially the
outdated ones. Some examples include Poly boot . B
and Anti EXE.

9. Macro Virus
 Macro viruses target applications and software that
contain macros. These viruses can carry out series of
operations affecting the performance of the program
or software. Some examples of macro viruses are
O97M/Y2K, Bablas, Melissa.A, and Relax.

10. Directory Virus
 Directory viruses change file paths. When you run
programs and software that are infected with directory
viruses, the virus program also runs in the
background. Further, it may be difficult for you to
locate the original app or software once infected with
directory viruses

11. Polymorphic Virus
 Polymorphic viruses use a special method of encoding
or encryption every time they infect a system. With
this, antivirus software finds it hard to locate then
using signature searches. They are also capable of
replicating easily. Polymorphic viruses include Satan
Bug, Elkern, Tuareg, and Marburg

12. File Infector Virus
 This virus also infects executable files or programs.
When you run these programs, the file infector virus is
activated as well which can slow down the program
and produce other damaging effects. A large block of
existing viruses belongs to this category.

13. Encrypted Virus
 This type of virus uses encrypted malicious codes
which make antivirus software hard to detect them.
They can only be detected when they decrypt
themselves during replication. Although they don’t
delete files or folders, they can badly affect PC
performance.

14. causes of computer virus
 Some Common Sources of Computer Virus
Infection

15. Virus sources
 Downloading Programs. Programs that contains the
downloadable files are the commonest source of
malware such as freeware, worms, and other
executable files. ...
 Pirated or Cracked Software. ...
 Email Attachments. ...
 Internet. ...
 Booting Data from Unknown CDs. ...
 Bluetooth. ...
 Un patched Software.

16. What are the main causes of
computer virus Infections ?
 Computer virus infections are the nightmare of a business
owner. That’s hardly a surprise, though. After all, what business
owner wants to deal with computer infections that can cause
severe damage to their data and important documents?
 It’s no secret that computer viruses can cause companies to lose:
 Client data
 Customers
 Money
 Brand credibility
 And much more… However, these are the main concerns that take the
spotlight. That’s because they’re the ones that can cost you your
business. So it’s not surprising why many business owners worry about
their data and important documents being exploited. Well, the best
way to deal with these concerns is to learn where they come from.

17. how to protect computer from
viruses
 Keep software up to date. ...
 Don't click on links within emails. ...
 Use free antivirus software. ...
 Back up computer. ...
 Use a strong password. ...
 Use a firewall. ...
 Minimize downloads. ...
 Use a pop-up blocker.