Computer Virus
A computer virus is a type of
malicious software that, when executed, replicates itself by modifying other
computer programs and inserting its own code. When this replication succeeds,
the affected areas are then said to be "infected" with a computer
virus.
Virus writers use social
engineering deceptions and exploit detailed knowledge of security
vulnerabilities to initially infect systems and to spread the virus. The vast
majority of viruses target systems running Microsoft Windows, employing a
variety of mechanisms to infect new hosts,[8] and often using complex
anti-detection/stealth strategies to evade antivirus software. Motives for
creating viruses can include seeking profit (e.g., with ransomware), desire to
send a political message, personal amusement, to demonstrate that a
vulnerability exists in software, for sabotage and denial of service, or simply
because they wish to explore cybersecurity issues, artificial life and
evolutionary algorithms.
Computer viruses currently cause
billions of dollars' worth of economic damage each year, due to causing system
failure, wasting computer resources, corrupting data, increasing maintenance
costs, etc. In response, free, open-source antivirus tools have been developed,
and an industry of antivirus software has cropped up, selling or freely
distributing virus protection to users of various operating systems.
The term "virus" is also
commonly, but erroneously, used to refer to other types of malware.
"Malware" encompasses computer viruses along with many other forms of
malicious software, such as computer "worms", ransomware, spyware,
adware, Trojan horses, key loggers, rootkits, boot kits, malicious Browser
Helper Object (BHOs) and other malicious software. The majority of active
malware threats are actually Trojan horse programs or computer worms rather
than computer viruses. The term computer virus, coined by Fred Cohen in 1985,
is a misnomer. Viruses often perform some type of harmful activity on infected
host computers, such as acquisition of hard disk space or central processing
unit (CPU) time, accessing private information (e.g., credit card numbers),
corrupting data, displaying political or humorous messages on the user's
screen, spamming their e-mail contacts, logging their keystrokes, or even
rendering the computer useless. However, not all viruses carry a destructive
"payload" and attempt to hide themselves—the defining characteristic
of viruses is that they are self-replicating computer programs which modify
other software without user consent.
9 Types Of Computer
Viruses
1.
Boot Sector Virus.
Even though this virus has now
become obsolete, it still pops out in one way or the other. This virus got
attention when floppy disks were used to boot a computer. In modern computers,
this virus could appear on the “Master Boot Record”. In the partitioned storage
device of your computer, it is the first sector to take place.
However, thanks to the fact
evolution of Internet, the threat of this virus is now mitigated.
2. Web Scripting Virus.
Similar to the hyperlinks that
we used in Microsoft Word, many websites rest on codes to provide engaging
content to their users. For example, since the trends of watching videos online
have now become very popular – more than 2 Billion Videos are streamed on
Facebook every day, these videos also execute a specific code.
These codes can be exploited
and it is very troublesome to note that this exploitation has taken place on
some very notable sites. All the hackers have to do it to leave a comment in
the Comments Section of the website which contains that code. Thus, even
without the Webmaster knowing it, the code gets exerted into the site.
3. Browser Hijacker.
Ever faced a problem where the
homepage of your web page gets automatically directed to a particular site?
Well, that is the most common way by which this ransomware hijacks your
browser.
While its visual effects might
epitomize the threat, this hijacker is nothing more than a tactic to increase
income from web ads. However, if you still want to clean your computer from
this virus, give Soft2Secure a go.
4. Resident Virus.
After inserting itself
directing into the memory of your system, this virus has the capability to take
a number of actions. One of its more troublesome features is its ability to run
away. Leaving behind the file which was originally infected, this virus has the
ability to run on its own.
5. Direct
Action Virus.
Similar to the Vienna virus
which shocked computers in 1998, this virus comes into action after you have
executed the file. The load is delivered to your computer and the virus becomes
active.
However, this virus has a
limitation. It takes no action unless the file which is infected gets
implemented again.
6. Polymorphic Virus.
One of the factors that
epitomize the usefulness of this virus is its ability to evade. The Antivirus
programs that are enabled on our computers detect the presence of any virus by
detecting its code.
Polymorphic virus has
exploited this limitation beautifully as it changes its code every time the
infected file is executed. Thus, it becomes nearly impossible for any ordinary
antivirus to track it down.
7. File Infector Virus.
Although the word “file” in
its name might suggest otherwise, this virus does not take the help of files
every time. In fact, the file is only the starting point as the file infector
dwarfs the first file after which it re-writes the file.
8. Multipartite Virus.
If you have read carefully the
aforementioned viruses, you might have noticed that they use two methods for
their transmission. Either they use one method or a single payload is
delivered.
However, this virus wants to
claim both. Depending upon the operating system of your computer or the files
that exist on your computer, it might use any of the two methods to spread.
9. Macro Virus.
Appearing in the form of a
word document which seemingly links the user to pornographic websites, Melissa
is one of the most known Micro Virus. Going one step further, this virus not
only exploits the user but also his/her friends by mailing the copies of the
infected virus document to the contact list.
