What is a Computer Virus-Types Computer Virus -What Does virus Do?

A computer virus is a malicious code or program which has been designed in such a manner , so that it will alter the way a computer operates & will spread from one computer to another.

This post is significant in understanding the various types of virus and how do they corrupt & infect the system.

What is a Computer Virus?

A computer virus is a malicious code written to disrupt the computer and alter the way it operates. A computer virus can self replicate by inserting itself into other programs.Certain programs that carries downloadable files usually becomes the transmitter of such virus. The first wide spread computer virus for an IBM PC operating system was called Brain.

Initially virus started spreading around by Floppy disc. Trojan usually spreads in the form of video down-loader or video converter etc. Certain virus gets transmitted by Emails. In some cases even, if you do not click on those Emails still your computer will get infected.

Different Types of Virus:

• Boot sector virus.
• Direct Action virus.
• Resident virus.
• Multipartite virus.
• Polymorphic Virus
• Overwrite virus.
• Spacefilter virus.

Most widely Spread Viruses are mentioned below:

• Malware
• Virus
• Worms
• Spyware
• Trojan
• Ransom ware
• Adware

Video Tutorial: What is a Computer Virus-Types Computer Virus -What Does virus Do?

Some Most destructive Viruses are stated below:

A] Mellisa Virus: It was a mass mailing virus introduced by David L Smith in the Year 1999. He was arrested by FBI for creating this virus and was put behind the bars for 20 months. It used to attack the network and overload it.

B] Code Red Virus: It was first detected in 2001. It used to attack the web server IIS of Microsoft and then it used to crash the server completely. It affected more than 20 lakhs server. It was a deadly virus which caused great financial loss.

C] My Doom Virus: Was introduced in 26th January 2004. It is sent to your computer via Emails. Subsequently it used to crash the computer systems. It is assumed, around 2 Million computer system were affected by this virus. It caused a huge financial loss.

D] Wannacry Ransomware Virus: It came into existence in 2017.It used to enter the computer via emails or a 3rd party software. After installing itself it used to lock  the computer.  Subsequently a message used to pop up asking the user to pay a certain amount to get the computer unlocked.If the user paid that amount then he or she used to receive a key to unlock the computer or else it used to crash the computer.

E] I Love You virus: It was regarded as one of the most dangerous virus. It surfaced in the year 2000.It affected around 10 % of computers globally. It not only used to crash the computer, but in case the computer was connected with a server then it used to affect the server as well. It impacted Banking sector to a great degree.

Few more Key Viruses:

Go Brut-It’s a fairly new virus, once it moves into your computer, it has the ability to crack password it slows down the system and causes damage to the computer.

Trojan Glupteba- It comouflages by operating to be a legit software and communicates with the IP address and in the process collects your confidential information.

Storm Worm - It is basically a Trojan. It uses news headlines as a means to create curiosity and encourages the user to go through that news. Once it manage to infect your PC, then it uses the same as a source to attack other PC's.

Anna Kournikova - This virus spreads by an Email that shows the image of Anna Kournikova, who is a famous tennis player. The idea is to irritate the user and not harm the PC.

Stuxnet- This virus is although illegal but it was legally created by USA and Israeli defence force for thwarting and disrupting Iranian Nuclear plans.

10 Latest virus & Malware threats in 2020:

• Fake Windows update.
• RaaS.
• Fleeceware.
• Social Engineering.
• Artificial Intelligence attacks.
• Clop Ransomware.
• Zeus Gameover.
• News Malware attacks.
• loT device attacks.
• Cryptojacking.

Top 10 dangerous Financial Malwares :

• Citadel.
• Torpig.
• Bugat.
• Zbot/ Zeus.
• Shylock.
• CryptoLocker.
• Carberp.
• Ice ix
• Zeus Gameover.
• SpyEye.

SOCIAL ENGINEERING ( in the context of Information security) : 

The art of influencing or manipulating people in such a way , so that they will end up disclosing their confidential information in good faith, is called as Social Engineering.

Cyber criminals usually trick people into giving their password or Bank details. After accessing all the relevant information about the user, these criminal gets the free hand to control the computer of the user by keeping the user in dark.

This leads to online fraud, e - mail fraud, Phising attacks & various other fradulent activities via digital medium.

It is relatively difficult to heck computers or access Bank details or password , especially when the user is reluctant to make a person privy to all such confidential information. However, it is possible to hoodwink people into believing something, which may not be the case in reality & in the process extract the information.

The user must be mindful of the fact that, greed makes us poor & ignorance is always frightful. We should not get lured by any lucrative offer.

We must resist the temptation to give away certain information thinking that the same will help us to make some quick money. We must not reveal any confidential information under any circumstances to a stranger , as we are not in a position to go for a background check of such individuals or sources.

It is advisable not to entertain unknown sources in such matters. In the pretext of helping the user or using some other other ploys, these Cyber criminals takes out the information from the user & commits financial crimes.

The modus operand of such criminals are very simple & that is to exploit human behaviour. Safety & security comes first. No compromise whatsoever with security measures. Let it be manual or technical, it should be spot on.

What causes computer virus?

There are certain programs that contains downloadable files and such files are usually considered as the major source of malware. Internet, Blue tooth & e-mail attachments are also  considered to be carriers of computer virus.

What are the top viruses of all times?

The top virus of all times are mentioned below:

• Brain.
• Anna Kournikova.
• Storm Worm.
• Morris Worm.
• Conficker.
• Sasser & Netsky.
• My doom.
• Stuxnet.
• I love you virus.
• CryptoLocker.

Difference between a Macrovirus & a Polymorphic virus?

A Macrovirus will infect macro applications inserted in Microsoft Office or  PDF files.
A Polymorphic virus alter it's source code each time, to avoid getting detected by anti virus software.

What is the typical spreading method for financial malware?

Two major methods have been observed:

1) Drive by downloads - This is something which takes place when users click a deceptive pop - up window.

2) Spam Campaigns - In such a campaign the user is sent across an e- mail with wrong information or a link attached with the e- mail.

Such e- mails are deceptive because the user is given an impression that it is about a lucrative offer or an important notice / invoice order. As soon as the user, clicks on such links or downloads the file, the system gets infected.

Conclusion:

A Computer virus  pose a great challenge for the well being of the Computers. It's a threat which cannot be countered until & unless, the user knows how to take necessary actions to negate the threat. Unequivocally we can say, Anti virus software is the best means to protect the system. At the same time user must refrain from clicking any link sent from unknown sources & we must be conscious while downloading any files, or attachments from e-mails. By being alert & awake, one can protect his or her computer system.