Dangerous Computer Virus - TechieSurge (2018)

31 Most Dangerous Computer Virus (Exclusive) | 2019

Have you ever encountered with the term “Virus“? If not, then you’re lucky enough but if yes, then you’re gonna know more about the most recent and previous deadliest viruses of all time.

Have you ever used a PC(Personal Computer), I guess most of you have used it and nevertheless a situation have arrived to you like your Pc’s hanging or something else like that.

That may be because of your Pc lacking latest updates or there may be a person called “Virus” sitting alone, slowing down your processing time of Pc and/or infecting a part of your PC temporarily or permanently.

Here is the list of the deadliest “Viruses” of all time that you might have heard it earlier and if NOT then hold my hand and get started from here now.

Before getting started let’s do some warm-up first…

Most Dangerous Computer Virus - TechieSurge (2018)

What is a Computer?

A computer is a device or a machine that takes an input from the user and processes, functions and operates as per given instructions that generates an output in the form of information, signal.

What is Malware?

In simple terms, a malware or malicious software is a program especially designed to harm the computer system intentionally. A Malware includes stealing, encrypting or deleting sensitive data, hijacking, remotely controlling into the host server, surveillance on a host without their permission.

What is a Computer Virus Definition?

A computer virus is a program or a software(malware) that when successfully executes on a computer multiplies in number and affects the particular area of the computer as per the codes written by the constructor/coder. When the codes success in replication it’s said to be affected by a computer viruses.

Dangerous Computer Virus #1

Melissa came into existence in 26 March 1999 when a person named David L Smith gave birth to the deadly virus. This is a kind of virus that injects to your device via email that comes to you with a name “list.doc”. When you click on the attachment, the file(virus) automatically replicates itself and spread throughout your computer and the first 50 email list of your Microsoft Outlook will get an automated email with a message ” Here is a document you have asked for… don’t share with anyone else:-)”. The virus affected only Microsoft Word 97 or Word 2000. The email actually has a potential to block server mails and corporate mails that affected Microsoft company in no time.

Lastly FBI came to rescue the world and arrested the man behind all this mayhem in the online world. He had to pay a fine of $5,000.

Dangerous Computer Virus #2

Based on vbs(Virtual Basic Script), ILOVEYOU virus was created by Philippine’s Onel De Guzman and Reonel Ramones in 4 May 2000. This virus initially exploded all the mailing list of the users around the world by sending the mail with an attachment that says – “LOVE-LETTER-FOR-YOU.TEXT.vbs”as it’s file name attached to the email. It crashed all the PCs around the world whoever opens this attachment. Afterwards it shares the same mail to the first 50 emails from the infected user’s email list. This virus caused a total 10% of the world’s PCs which eventually costs for around $10 billion across the internet.

Dangerous Computer Virus #3

Another biggest virus of the year 2001 was Code Red I and Code Red II which originated from China on 15 July and on August, respectively. Both worms affected the PCs using Windows 2000 and Windows NT. The flaw here was buffer overflow problem that means when a machine starts receiving more information than its buffer then it starts to overwrite the adjacent memory.

It majorly attacked the White House of USA. The Code Red uses a Distributed Denial of Services(DDOS) which at the same time attacked to the computers of the White House, contacting to the servers at a same time lead to overloading of machines.

Windows 2000 was infected by Code Red II never obeys the owner of the virus. This is because this virus creates a backdoor into the owner’s computer allowing a remote user to operate and control the victim’s machine. In computing, it’s called System Level Compromise, which is a flaw to the virus’ owner. Also the owner of the virus can access the victim’s PC remotely and can use the stored information in any illegal activities. So there’s a threat to the victim’s computer and risk to the criminal offences.

While Windows NT was affected by Code Red Virus that made the server running on Windows to crash more than usual. But it’s not as bad as Code Red II virus. Its not that much bad as Code Red II.

Dangerous Computer Virus #4

Nimda became another proprietor on the internet in 8 September 2001. It’s just the opposite of “Admin”  when observe from backwards. It was first observed in China authored by few Chinese people. It was written and executed in C++ affecting Windows XP and Windows 95. Unlike other viruses it deployed using emails, shared folders, networks of computers and file transfers. One of which is behind the bars for lifetime.

Dangerous Computer Virus #5

In 2003, SQL Slammer(SQL worm or slammer worm) made it spread all over the server’s internet. It primarily slowed down the internet servers response time and minimized the traffic rate that too within 10 minutes.

The worm was based on Black Hat Briefings by David Litchfield. It is a small set of codes that when installed on a certain PC gets spread to other system on the internet via generating random IPs(Internet Protocol). This chain of spreading the code recurs itself continuously and continues to dampen the routers and the host using unlatched version of Microsoft SQL Server Resolution Service listening on UDP port.

Dangerous Computer Virus #6

Mydoom is an internet worm which is still a mystery that who created this virus. Its first found on 26 January 2004. This worm has deteriorated around 20-30 per cent of the email listings of the internet and is assumed to belong from Russia.

Major websites moved from old URL to new URL to avoid this email attack via DoS(Denial of Services) system. Consequently it slowed down the internet traffic worldwide. Around 600,000 to 700,000 computers of the United States were affected by the worm. While one per cent were found in its hone country Russia. This incident depicts of Russia’s higher level of computer security.

Major tech companies like Microsoft and SCO were affected by this killer Mydoom virus. F-Secure antivirus expert Mikko Hypponen called Mydoom the “worst email worm incident in virus history”.

Dangerous Computer Virus #7

A Sasser virus was created by a German student named Sven Jaschan on April 2004. Sasser was an internet worm that rose among the Windows users and infected millions of computers causing crash or slow down leading to huge losses.

This worm runs on a buffer vulnerability in Local Security Authority Subsystem Service(LSASS) that ensures the safety policy of local accounts causing crashes to the PC. The name of the virus comes from the LSASS itself. This viral virus affected some prominent infrastructures like hospitals, airlines, new agencies and public transportation.

Dangerous Computer Virus #8

The Storm Worm(as named by Finnish company) was first discovered on 17 January 2007. It uses a backdoor(a backdoor is a method by which a system bypasses a normal authentication or any encryption that a victim’s system prevails). The worm affects only Microsoft Windows OS installed on PC. The worm started to attack thousands of computers in Europe and United States with a message “230 dead as storm batter Europe”. At that time, there were about six subsequent waves attack on weekends. This storm worm accounts for about 8% of malware infections around the world.

According to PCWORLD(a global computer magazine) said that the storm worm majorly belong to Russia and is only traceable by Russian Business Network.

Dangerous Computer Virus #9

In the late 2009, Conficker(also known as down, downadup or kido) spread across millions of Windows PC of the important firm. It was first observed in Ukraine and China. This created a remotely controlled computer bot with huge army of destructors. This could be used for stealing many financial data and sensitive information stored in a computer.

While this tragedy was misled by a number of anti-viruses to cope up the problem and helped tackle the army of destructors.

Dangerous Computer Virus #10

Zeus is a Trojan horse that steals the data from the user entry and form grabbing. Zeus was sprayed on all the PCs through regular downloads and phishing schemes. It was first observed on the year 2007, when it is used to steal information from United States Department of Transportation. In 2009, it was discovered by security company Prevx that it captured 75,000 FTP(file transfer protocol) servers of companies like NASA, Bank of America, ABC, master.com, Oracle, Amazon, Play.com and  BusinessWeek.

Later, in the year 2009 it handled around 3.6 millions of computers of United States. The worm spread to 1.5 millions of computers through phishing messages sent through Facebook. A total 9 million of emails were sent to users with the purpose of infecting the computers through Zeus Trojans.

Finally on 3 November 2009, a couple from United States got arrested for stealing personal and sensitive data.

This proved another disaster by FBI on 2010 as it was used to steal data from US computers and steal around $70m of wealth.

Dangerous Computer Virus #11

The CIH(chen ing hau) virus, also known as Chernobyl was first found in June 1998 in Taiwan. According to the Taipei Authorities, Chen ing hau(CIH) wrote the deadly CIH virus.

In Korea, as many as one million computers were affected by CIH virus exploding about $250m. 200, 100 and 10 computers were infected in Singapore, Hongkong and India respectively.

The virus spread throughout the countries via pirated softwares.

Dangerous Computer Virus #12

OnTheFly virus is a VBS(visual basic script) based worm. It was created with a worm construction kit. It became most famous as it’s named after famous tennis player Anna Kournikova, to attract more user to fall into prey.

OnTheFly was limited to taking up spaces in mailboxes and consuming system resources. Millions of computer got infected due to this unusual worm, but the FBI came to reduce the flaw and counteract the viral internet worm. About $166k+ were consumed by this deadly computer virus.

Dangerous Computer Virus #13

Beast is Windows-based backdoor Trojan horse, more  commonly known as Remote Administration Tool(RAT). Designed and coded in Delphie by Tataye in 2002, became popular in the internet in no time due to its unique features.

Beast has the ability to bypass firewall and also fuse-in with some antiviruses or firewall process.

This deadly virus gave the intruder permission to control remotely the user’s computer and can access the file manager, registry editor, webcam, and many options.

Dangerous Computer Virus #14

Sobig.F is the most deadly virus of the year 2003 as it occupied almost all the internet users through email services. The virus when executed in a single device then replicates the applications to resend the attachment to all the emails attached to the earlier ones.

This slowed down all the global internet services of the users.

Sobig spread in its two variants – Sobig.E and Sobig.F. It’s still not known that who made this virus and for what purpose.

Dangerous Computer Virus #14

Blaster also known as Lovesan was created by unknown person in 2003 with Distributed Denial of Services(DDoS). Damaging almost hundreds of millions of computer users with a message that says – “I just want to say LOVE YOU SAN”

Not only this there are a number of other Blaster viruses which distinguishes from other variants:

Blaster.B, Blaster.C, Blaster.D, Blaster.E, Blaster.F, Blaster.G, Blaster.H.

Just after activation of the codes, it’ll show a message to “shut down the computer”.

Dangerous Computer Virus #15

The Morris worm(internet worm or great worm) was first noticed on 1988. This worm is considered as the first worm to gain all media attention and also highlighted few of the major drawbacks of the internet services that is to be maintained and rectified. It was originated from Cornell, MIT.

Since it spread like a fire in the government firms of the United States and crashed, slower down all the internet services. The estimated cost of repairing and removing the worm costs a $200 to $53,000.

Dangerous Computer Virus #16

The Brain virus considered to be the first PC virus. It infects the 360 kilobytes, 5.25 inch of Floppy Disk. It is sometimes referred to as first virus discovered yet. It is created by Basit Farooq Alvi from Pakistan on 1986.

The virus does no intentional damage to the system. But it can slow down your disk access and cause timeouts. This will simply make your data stored on floppy disks lost completely.

Dangerous Computer Virus #17

Elk Cloner is a boot sector virus designed by then-high school student, Richard Skrenta around 1982. Its major ability is to show nothing more than annoying pop-ups with a message. It did not spread to others except Skentra’s freinds and his Maths teacher. Further he distributed a pirated copy of softwares with the virus and is spread to all the other students.

Dangerous Computer Virus #18

Klez is another most destructive virus of their time. It was first discovered on October 2001 in Guangdong, China. Nobody knows who created this deadly virus. But it does simply spoofing the email addresses in the sender’s address and has ability to offer the computer by previewing or opening the message without downloading the attachment. It had damaged a total of $19.2 billion.

Dangerous Computer Virus #19

Stoned is a large group of boot sector virus found in 1988. Some prominent members of the stoned virus are Michelangelo virus that rose in the 1990s and Angelina virus that woke up on 1994.

The virus was created by a student at Victoria University in Wellington, New Zealand.

If it somehow attached to the same folder that your installation directory is then it can even delete your antivirus program. Interestingly, it would send an auto-generated email containing body text, attachment and subjects to send to the recipients.

Dangerous Computer Virus #20

Jerusalem file virus spread across all over the computers in Jerusalem on 1987. It was first found on Jerusalem University that’s why it’s named as Jerusalem virus. Jerusalem is a DoS file that comes in many variant under .com and .exe file.

Jerusalem infects both the .com and .exe file under DoS. After the successful execution of virus, it stays in the memory even after the program has been terminated. The virus then infects all the programs after the first infected program runs.

The Jerusalem and its variant has a bug that makes them infect all other programs already installed on the computer and causing them to consume all the storage space.

Dangerous Computer Virus #21

Beagle also known as Bagle, is a large herd of email worm that came to existence on January 2001. Its creator is still unknown. Beagle was sent to users via emails with a password protected .zip files and password set in the body of the message.

Beagle gets its name from file bbeagle.exe which is the original name of the file and its many variants comes inside the same folder of beagle.

In general they are about 20,000 bytes in length and/or 100,000 bytes. Most of them are found as Beagle.P and Beagle.DW form.

Dangerous Computer Virus #22

Slammer(also known as Sapphire, Helkern or SQLExp) was found on January 2003, an internet worm comes in an UDP packet having a file size of 404 bytes.

It was the fastest and largest spreading virus of its time. The worm actually was a simple piece of code written in a Assembly Language.

For Slammer, it took around 15 minutes to spread across 90 per cent of all vulnerable host servers, 359,000 computers in total, 13 root DNS servers went down, and a huge loss to all the major firms and industrialist. This virus costed between $960 million and $1.2 billion in just five days.

 Dangerous Computer Virus #23

Barrote is a computer virus runs on an Assembly Language, first found on 1992 created by OSoft(group). Its first observed in Spain and works on .com and .exe file names.

Major feature of this virus is to show vertical lines on the screen. There are total 17 variants of the Barrote.

Dangerous Computer Virus #24

Solar Sunrise is a computer virus that runs on a Solaris platform and is one and only virus that works on Solaris, found on 1998 and is created by an unknown person.

This virus had took control over 500 military, private sector and government computers in United States. The bunch of hackers cracked into military computer systems and also inserted a malware. This incident throws light on the fact that the computer system lacks the security patches at different level.

Dangerous Computer Virus #25

Nuclear RAT(Remote Administration Tool) is a Trojan horse backdoor infecting all the Microsoft Windows system(Windows NT, 2000, XP, 2003), discovered in the year 2000. It uses a creature server, client and server to take control over a remote computer. It fools the system’s firewall and gain access to the host computer to hijack the system’s servers.

Various alias names formed after Nuclear RAT. So far the one person who made this Trojan horse is Caeser2k.

So far now it can attack on a computer having Windows NT, Windows 2000, Windows XP, Windows Server 2003.

Dangerous Computer Virus #26

WannaCry is a ransomeware virus spread across the globe mainly Russia, US, India and Ukraine, in May 2017. WannaCry originally called as, WanCrypt or WanaCrypt0r and WanaDecrypt0r is a ransomeware worm that attacks on Microsoft Windows that created havoc in airports, hospitals, universities and many other institutes.

It has spread to 150 countries. It uses RSA-2048, so only way to retrieve the files is by backup or pay the hackers amounting 300 USD using Bitocoin payment channel. After 72hrs of initialisation of virus the amount to paid increases to 600 USD.

And after 7 days of the initialisation the malware starts to delete the files on the computer.

Dangerous Computer Virus #27

Stuxnet was the most popular worm that runs on C programming language on June 2010. It exists as .exe, .sys, .dll and works on all Microsoft Windows platform.

It was first noticed when used to tackle the uranium enrichment program and to prevent President Mahmoud Ahmedizenad from building a nuclear weapon.

It’s not like other worms that was built to steal passwords, encryption, hijacking, or any other harm but designed for the purpose of disabling the unwanted industrial use.

Dangerous Computer Virus #28

Petya also known as NotPetya is a ranosmware that sprays on Microsoft Windows via LAN. It was first found on June 2017, in United States.
More than 64 countries were affected with this malware. It uses .dll extension file having two variants, the original 2016 variant and the 2017 variant.

Dangerous Computer Virus #29

Flashback is another trojan horse found on September 2011 by an antivirus company Intego. It’s major host is Mac OS X that only executes when a file has been downloaded from a bogus web page. After successful installation of flash player, which was a mime of original Adobe Flash Player.

A flashback works on a JavaScript and once executed, can be controlled and run from a remote computers. Each bot was given a unique id to control the server on the internet. So the computer were not infected unless and until the file containing malware is downloaded from a bogus online webpage. Or it can be transferred manually from one user to another.

Dangerous Computer Virus #30

Cryptolocker is a popular ransomware trojan operating on Microsoft Windows which spread via emails and is considered as the first ransomware trojan. It comes with a .exe file extension packed in a zip file attached with an email.

Cryptolocker’s payload encrypts the victim’s file using a unique method of encryption that is quite difficult ot crack(RSA-2048) and refused to unlock the files until ransom of $500 in prepaid cash or Bitcoin is paid. The payment should be made under 72hrs of initialisation of virus and if not then it will starts delete all the files on the victim’s computer.

Dangerous Computer Virus #31

Pikachu is another worm that runs on Microsoft Windows which is designed using Visual Basics(VB) 6.0.

It’s an email worm sent to the recipient with a file name “Worm.Win32.Pikachu” or “Pikachu”.

The name arrives from the popular series of cartoon called “Pokemon” and was spread via emails with a filename “Pikachu.Pokemon.exe”. Having a file size of 32 kilobytes.

When successfully installed, the worm runs and overwrites all the files to C:\AUTOEXEC.BAT file with a set of instructions and delete all the files from Windows and Windows directory.

Tips to protect from Dangerous Computer Virus:

◆ Always keep your computer softwares updated.

◆ Use an Antivirus program on your computer(free).

◆ Never click on the unknown email(especially that has no name or saved in spam)

◆ Always make use of Windows Firewall.

◆ Use a strong password.


So these are most renowned 31st viruses of all time.

Isn’t it the viruses that lead to the birth of Anitviruses that now protects us from unknown infecting files.

Would you not like to know how to protect them from various virus and other bugs on the internet.

Now can you tell me which virus is your favorite and why?


Indra Kumar

He is a passionate writer or you can say a blogger. He loves to share his views, opinions, knowledge about technological gadgets, products, etc. He has a keen interest in reading fictious, adventurous, thrilling, biographical books.


  1. I’m really inspired along with your writing talents and also with the structure in your weblog.
    Is this a paid subject or did you customize it yourself?

    Anyway keep up the nice high quality writing, it’s rare to look a great weblog like this one today..

    1. No it’s not a paid blog but I manmage by myself
      And Thanks for the complement!!

Leave a Reply

Your email address will not be published. Required fields are marked *