Ransomware is a kind of malware that takes your files hostage. You know in heist movies when the bad guy grabs someone and threatens them in return for money? Ransomware works much like that, except your computer is taken hostage by a faceless bad guy.

Released in September 2013, CryptoLocker spread through email attachments and encrypted the user’s files so that they couldn’t access them.

The hackers then sent a decryption key in return for a sum of money, usually somewhere from a few hundred pounds up to a couple of grand.

With some of the hacking attempts, System Restore or recovery software worked. Although with many of the infected computers, if the victims didn’t pay up they’d lose all their files. Now is a good time to remind you to always back your files up!

In June 2014, Operation Tovar took down Evgeniy Bogachev, the leader of the gang of hackers behind CryptoLocker. In February, the FBI offered a cool $3 million reward for Bogachev.

Cost of the malware: With 500,000 victims, CryptoLocker made upwards of $30 million in 100 days.

2. ILOVEYOU
While ILOVEYOU sounds like a cheerful bon mot you might find printed on the inside of a Valentine’s Day card, it’s actually far, far more sinister than that. ILOVEYOU is one of the most well-known and destructive viruses of all time.

It’s been 15 years since ILOVEYOU was let loose on the internet. By today’s standards it’s a pretty tame virus, but in 2000 it was the most damaging malware event of all time. Likely, ILOVEYOU inspired many hackers to wield their keyboard as a weapon.

3. MyDoom
MyDoom is considered to be the most damaging virus ever released—and with a name like MyDoom would you expect anything less?

MyDoom, like ILOVEYOU, is a record-holder and was the fastest-spreading email-based worm ever. MyDoom was an odd one, as it hit tech companies like SCO, Microsoft, and Google with a Distributed Denial of Service attack.

25% of infected hosts of the .A version of the virus allegedly hit the SCO website with a boatload of traffic in an attempt to crash its servers.

As well as targeting tech companies, MyDoom spammed junk mail through infected computers, with the text that said “andy; I’m just doing my job, nothing personal, sorry”. Who was Andy? Who knows.

In 2004, roughly somewhere between 16-25% of all emails had been infected by MyDoom.

Cost of the malware: $38 billion.

4. Storm Worm
Storm Worm was a particularly vicious virus that made the rounds in 2006 with a subject line of ‘230 dead as storm batters Europe’. Intrigued, people would open the email and click on a link to the news story and that’s when the problems started.

Storm Worm was a Trojan horse that infected computers, sometimes turning them into zombies or bots to continue the spread of the virus and to send a huge amount of spam mail.

Tip: never open a link in an email unless you know exactly what it is.

By July 2007, Storm Worm was picked up in more than 200 million emails.

Cost of the malware: An exact cost is yet to be calculated.

5. Sasser & Netsky

17-year-old Sven Jaschan created Sasser & Netsky, two worms, in the early noughties. Sasser & Netsky are actually two separate worms, but they’re often grouped together because the similarities in the code led experts to believe they were created by the same person.

Sasser spread through infected computers by scanning random IP addresses and instructing them to download the virus. Netsky was the more familiar email-based worm. Netsky was actually the more viral virus, and caused a huge amount of problems in 2004.

A German student, Jaschan was arrested when multiple tip-offs were reported to the police. Speculation suggested Jaschan had actually written the viruses to create business for his mother and stepfather’s PC business. Because he was under 18 when he wrote the virus, Jaschan spent his prison sentence on probation.

Even more interesting is Jaschan’s motivation. MyDoom was spreading rapidly at the time and Jaschan, a newbie coder, wanted to see what would happen if his bug could spread faster than MyDoom. Things quickly escalated from there.

Sasser was so effective it actually ground one third of the post offices in Taiwan to a halt, shut down 130 branches of a Finnish bank, and forced rail and transatlantic flights to be cancelled.

Cost of malware: Around $31 billion.

6. Anna Kournikova
What’s a tennis player got to do with a list of interesting viruses? Quite a lot, as it so happens.

We’re going to get this out of the way first: the Anna Kournikova virus is pretty tame compared to many on the list.

So in the early to mid-noughties, Anna Kournikova was one of the most searched terms on the internet. People were just very into tennis.

Jan De Wit, a 20-year-old Dutch man, wrote the virus as ‘a joke’. The subject was “Here you have, ;0)” with an attached file called AnnaKournikova.jpg.vbs. Anna was pretty harmless and didn’t do much actual damage, though De Wit turned himself into police anyway.

The mayor of the town came forward and said the city should be proud to have produced such a talented young man and offered him a job as a techie once he was finished his education.

Cost of the malware: $166,000.

7. Slammer
While most of the malware on this list strictly hit computers, Slammer was created with broader ambitions. Slammer is the kind of virus that makes it into films, as only a few minutes after infecting its first victim, it was doubling itself every few seconds. 15 minutes in and Slammer had infected half of the servers that essentially ran the internet.

The Bank of America’s ATM service crashed, 911 services went down, and flights had to be cancelled because of online errors. Slammer, quite aptly, caused a huge panic as it had effectively managed to crash the internet in 15 quick minutes.
8. Stuxnet
Stuxnet is easily the scariest virus on the list as it was built by government engineers in the US with the intention of obstructing nukes from being built in Iran.

Yes, you read that right. Who needs to target email when they can gun for nukes?

Stuxnet spread by a USB thumb drive and targeted software controlling a facility in Iran that held uranium. The virus was so effective it caused their centrifuges to self-destruct, setting Iran’s nuclear development back and costing a lot of money.

Stuxnet is the first real venture into cyberwar and it definitely asks the question as to what will come next. The idea of digital weaponry is pretty scary, isn’t it?

Cost of the malware: Unknown.

So there you have it: while viruses and malware might seem like a myth drummed up by tech companies, they are a very real threat that have caused billions in damage.

This entry was posted on Mon Feb 22, 2016 filed under digital trends , online security and online threats

محمد سامي قاسم
المستوي الرابع قسم اتصالات
mohamed samy kassem

The ILOVEYOU virus is considered one of the most virulent computer virus ever created.

2. Code Red

Code Red first surfaced on 2001 and was discovered by two eEye Digital Security employees. It was named Code Red because the the pair were drinking Code Red Mountain Dewat the time of discovery.

3. Melissa

Named after an exotic dancer from Florida, it was created by David L. Smith in 1999. It started as an infected Word document that was posted up on the alt.

4. Sasser

A Windows worm first discovered in 2004, it was created by computer science student Sven Jaschan, who also created the Netsky worm.

5. Zeus

Zeus is a Trojan horse made to infect Windows computers so that it will perform various criminal tasks.

6. Conficker

Also known as Downup or Downadup, Conficker is a worm of unknown authorship for Windows that made its first appearance in 2008.

7. Stuxnet

Believed to have been created by the Israeli Defence Force together with the American Government, Stuxnet is an example of a virus created for the purpose of cyberwarfare, as it was intended to disrupt the nuclear efforts of the Iranians.

8. Mydoom

Surfacing in 2004, Mydoom was a worm for Windows that became one of the fastest spreading email worm since ILOVEYOU.

9. CryptoLocker

CryptoLocker is a form of Trojan horse ransomware targeted at computers running Windows.

10. Flashback

Though not as damaging as the rest of the malware on this list, this is one of the few Mac malware to have gain notoriety as it showed that Macs are not immune.

virus attacks
March 19, 2019 | sayed kenawy | information security
What is the most famous virus attacks in the world?

45 Responses to “virus attacks”

Mohamed mostafa March 19, 2019 at 8:05 pm
What is the most famous virus attacks in the world?

1-The Morris Worm

On November 2, 1988, the worm was released and within 24 hours, an estimated 10 percent of computers connected to the internet were affected. The malware slowed down thousands of systems by creating files in temporary folders in an effort to replicate itself.

2-ILOVEYOU

It came with the attachment, “LOVE-LETTER-FOR-YOU.txt.vbs”. Once opened, it would send itself to everyone in the Outlook address book, making this one of the fastest-spreading viruses at the time.

3-MyDoom

MyDoom could further stop a device from running updates to security software!

The most concerning part of the virus was its ability to open a back-door vulnerability in systems for hackers to exploit. Some of these back-doors remain open.

4-WannaCry
It was particularly cruel: using a back-door exploitation in Microsoft Windows, it would encrypt all data on the device and hold your files to ransom,Once infected, a computer’s screen locks, showing a red warning and two countdowns, one until the ransom demand would rise and the other until files would be permanently deleted.

5-CryptoLocker

Released in September 2013, CryptoLocker spread through email attachments and encrypted the user’s files so that they couldn’t access them.

The hackers then sent a decryption key in return for a sum of money,

6-Storm Worm

Storm Worm was a particularly vicious virus that made the rounds in 2006 with a subject line of ‘230 dead as storm batters Europe’. Intrigued, people would open the email and click on a link to the news story and that’s when the problems started.

Storm Worm was a Trojan horse that infected computers, sometimes turning them into zombies or bots to continue the spread of the virus and to send a huge amount of spam mail.

7-Slammer

While most of the malware on this list strictly hit computers, Slammer was created with broader ambitions. Slammer is the kind of virus that makes it into films, as only a few minutes after infecting its first victim, it was doubling itself every few seconds. 15 minutes in and Slammer had infected half of the servers that essentially ran the internet.

8-Stuxnet

Stuxnet is easily the scariest virus on the list as it was built by government engineers in the US with the intention of obstructing nukes from being built in Iran.
Stuxnet spread by a USB thumb drive and targeted software controlling a facility in Iran that held uranium. The virus was so effective it caused their centrifuges to self-destruct, setting Iran’s nuclear development back and costing a lot of money.

محمد مصطفي صبري محمود
المستوي الرابع

Reply

Toka mohamed abdallah yousef March 19, 2019 at 8:19 pm
Resident Virus
Resident viruses live in your RAM memory. It can interfere with normal system operation which can lead to the corruption of files and programs. The most popular examples of resident viruses are CMJ, Meve, MrKlunky, and Randex.

Multipartite Virus
This type of virus can easily spread in your computer system. It is very infectious, performing unauthorized actions in your operating system, in folders, and other programs on the computer. They have the ability to infect both the executable files and the boots sector.
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.

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.

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.

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.

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 Polyboot.B and AntiEXE.
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.

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.

Reply

Mohamed noshy March 20, 2019 at 2:11 pm
What is the most famous virus attacks in the world?

1-The Morris Worm
On November 2, 1988, the worm was released and within 24 hours, an estimated 10 percent of computers connected to the internet were affected. The malware slowed down thousands of systems by creating files in temporary folders in an effort to replicate itself.
2-ILOVEYOU
It came with the attachment, “LOVE-LETTER-FOR-YOU.txt.vbs”. Once opened, it would send itself to everyone in the Outlook address book, making this one of the fastest-spreading viruses at the time.
3-MyDoom
MyDoom could further stop a device from running updates to security software!
The most concerning part of the virus was its ability to open a back-door vulnerability in systems for hackers to exploit. Some of these back-doors remain open.
4-WannaCry
It was particularly cruel: using a back-door exploitation in Microsoft Windows, it would encrypt all data on the device and hold your files to ransom,Once infected, a computer’s screen locks, showing a red warning and two countdowns, one until the ransom demand would rise and the other until files would be permanently deleted.
5-CryptoLocker
Released in September 2013, CryptoLocker spread through email attachments and encrypted the user’s files so that they couldn’t access them.
The hackers then sent a decryption key in return for a sum of money,
6-Storm Worm
Storm Worm was a particularly vicious virus that made the rounds in 2006 with a subject line of ‘230 dead as storm batters Europe’. Intrigued, people would open the email and click on a link to the news story and that’s when the problems started.
Storm Worm was a Trojan horse that infected computers, sometimes turning them into zombies or bots to continue the spread of the virus and to send a huge amount of spam mail.
7-Slammer
While most of the malware on this list strictly hit computers, Slammer was created with broader ambitions. Slammer is the kind of virus that makes it into films, as only a few minutes after infecting its first victim, it was doubling itself every few seconds. 15 minutes in and Slammer had infected half of the servers that essentially ran the internet.
8-Stuxnet
Stuxnet is easily the scariest virus on the list as it was built by government engineers in the US with the intention of obstructing nukes from being built in Iran.
Stuxnet spread by a USB thumb drive and targeted software controlling a facility in Iran that held uranium. The virus was so effective it caused their centrifuges to self-destruct, setting Iran’s nuclear development back and costing a lot of money.
محمد نصحى محمود محمد
المستوى الرابع اتصالات

Reply

خالد محمد عبد اللطيف March 20, 2019 at 6:45 pm
1-MyDoom
2-ILOVEYOU
3-Melissa Virus
4-WannaCry Ransomware Virus
5-Code Red Worm
6-Nimda
7-Sql slammer
9-Mebroot
ومن وجهة نظرى ان احطرهم واكثرهم استغلال لحد هذة الساعة هما
WannaCry Ransomware Virus
Sql slammer
وبالاخص فى الوطن العربى

Reply

Amina Ashraf March 22, 2019 at 10:11 pm
1. CryptoLocker
2.ILOVEYOU
It’s been 15 years since ILOVEYOU was let loose on the internet. By today’s standards it’s a pretty tame virus, but in 2000 it was the most damaging malware event of all time
3. MyDoom
MyDoom, like ILOVEYOU, is a record holder and was the fastest spreading email-based worm ever
4.Storm Worm
Storm Worm was a particularly vicious virus that made the rounds in 2006, people would open the email and click on a link to the news story and that’s when the problems started
5.Slammer
Slammer is the kind of virus that makes it into films, as only a few minutes after infecting its first victim, it was doubling itself every few seconds

Reply

mahmoud allam mahmoud March 23, 2019 at 6:25 pm
What is the most famous virus attacks in the world?

1-The Morris Worm

On November 2, 1988, the worm was released and within 24 hours, an estimated 10 percent of computers connected to the internet were affected. The malware slowed down thousands of systems by creating files in temporary folders in an effort to replicate itself.

2-ILOVEYOU

It came with the attachment, “LOVE-LETTER-FOR-YOU.txt.vbs”. Once opened, it would send itself to everyone in the Outlook address book, making this one of the fastest-spreading viruses at the time.

3-MyDoom

MyDoom could further stop a device from running updates to security software!

The most concerning part of the virus was its ability to open a back-door vulnerability in systems for hackers to exploit. Some of these back-doors remain open.

4-WannaCry
It was particularly cruel: using a back-door exploitation in Microsoft Windows, it would encrypt all data on the device and hold your files to ransom,Once infected, a computer’s screen locks, showing a red warning and two countdowns, one until the ransom demand would rise and the other until files would be permanently deleted.

5-CryptoLocker

Released in September 2013, CryptoLocker spread through email attachments and encrypted the user’s files so that they couldn’t access them.

The hackers then sent a decryption key in return for a sum of money,

6-Storm Worm

Storm Worm was a particularly vicious virus that made the rounds in 2006 with a subject line of ‘230 dead as storm batters Europe’. Intrigued, people would open the email and click on a link to the news story and that’s when the problems started.

Storm Worm was a Trojan horse that infected computers, sometimes turning them into zombies or bots to continue the spread of the virus and to send a huge amount of spam mail.

7-Slammer

While most of the malware on this list strictly hit computers, Slammer was created with broader ambitions. Slammer is the kind of virus that makes it into films, as only a few minutes after infecting its first victim, it was doubling itself every few seconds. 15 minutes in and Slammer had infected half of the servers that essentially ran the internet.

8-Stuxnet

Stuxnet is easily the scariest virus on the list as it was built by government engineers in the US with the intention of obstructing nukes from being built in Iran.
Stuxnet spread by a USB thumb drive and targeted software controlling a facility in Iran that held uranium. The virus was so effective it caused their centrifuges to self-destruct, setting Iran’s nuclear development back and costing a lot of money.

Reply

Ahmed Ali Elbaz Mohamed Hedihed March 27, 2019 at 8:52 am
What is the most famous virus attacks in the world?

1-The Morris Worm

On November 2, 1988, the worm was released and within 24 hours, an estimated 10 percent of computers connected to the internet were affected. The malware slowed down thousands of systems by creating files in temporary folders in an effort to replicate itself.

2-ILOVEYOU

It came with the attachment, “LOVE-LETTER-FOR-YOU.txt.vbs”. Once opened, it would send itself to everyone in the Outlook address book, making this one of the fastest-spreading viruses at the time.

3-MyDoom

MyDoom could further stop a device from running updates to security software!

The most concerning part of the virus was its ability to open a back-door vulnerability in systems for hackers to exploit. Some of these back-doors remain open.

4-WannaCry
It was particularly cruel: using a back-door exploitation in Microsoft Windows, it would encrypt all data on the device and hold your files to ransom,Once infected, a computer’s screen locks, showing a red warning and two countdowns, one until the ransom demand would rise and the other until files would be permanently deleted.

5-CryptoLocker

Released in September 2013, CryptoLocker spread through email attachments and encrypted the user’s files so that they couldn’t access them.

The hackers then sent a decryption key in return for a sum of money,

6-Storm Worm

Storm Worm was a particularly vicious virus that made the rounds in 2006 with a subject line of ‘230 dead as storm batters Europe’. Intrigued, people would open the email and click on a link to the news story and that’s when the problems started.

Storm Worm was a Trojan horse that infected computers, sometimes turning them into zombies or bots to continue the spread of the virus and to send a huge amount of spam mail.

7-Slammer

While most of the malware on this list strictly hit computers, Slammer was created with broader ambitions. Slammer is the kind of virus that makes it into films, as only a few minutes after infecting its first victim, it was doubling itself every few seconds. 15 minutes in and Slammer had infected half of the servers that essentially ran the internet.

8-Stuxnet

Stuxnet is easily the scariest virus on the list as it was built by government engineers in the US with the intention of obstructing nukes from being built in Iran.
Stuxnet spread by a USB thumb drive and targeted software controlling a facility in Iran that held uranium. The virus was so effective it caused their centrifuges to self-destruct, setting Iran’s nuclear development back and costing a lot of money.

أحمد على الباز محمد
المستوي الرابع اتصالات

Reply

Esraa Abdulbadea Ahmed March 27, 2019 at 5:32 pm
1-MyDoom
The most devastating computer virus to date is MyDoom, which caused over $38 billion in damages. In addition to being the most expensive virus to date, its effects were far-reaching and fast-moving. When a user was infected with the virus it creates network openings which allowed others to have access to your computer. In addition, the virus also had the ability to open random programs.

2_SoBig
Another harmful and expensive computer virus is SoBig. In 2003, the SoBig virus caused over $37.1 billion in devastation. This fast-spreading virus circulated through email as viral spam, and if exposed, the virus had the capability to copy files, emailing itself to others and causing serious damage to computer software and hardware.

3-ILOVEYOU
ILOVEYOU is another particularly malicious virus that spread quickly through email, websites and file sharing. The ILOVEYOU virus, or the “Love Letter” worm, affected more than 500,000 systems in 2000 and produced over $15 billion in damages, including $5.5 billion in the first week alone. The virus replicated itself and exposed itself to everyone in the owner’s contact list. This virus was a pioneer for other viruses, as it was one of the first to attach to an email.

4-Conficker
The Conficker virus caused over $9.1 billion in damages in 2007 and infected millions of computers around the world. The virus scanned computers for weaknesses and vulnerabilities, logged keystrokes and downloaded code from hacker-selected websites and more.

5-Code Red
One of the most well-known viruses to date is the Code Red virus. It caused over $2 billion in damages in 2001, and had the ability to break into computer networks and exploit weaknesses in Microsoft software. Once the virus infected the machine, it actively looked for other machines on the networks to attack.

6-Melissa
The Melissa virus was a particularly slimy virus that sent out infected Microsoft Word documents through Microsoft Outlook, delivering viral messages to everyone listed in the Outlook address book. The messages appeared to be coming from the Outlook owner, but was really the Melissa virus at work. A tell-tale indicator that Melissa had infiltrated your Outlook is if your contacts had received an email from you with the message: “Here is that document you asked for … don’t show anyone else.” There would be a word document attached, complete with the Melissa virus. In 1999, Melissa caused $1.2 billion in damages.

7-SQL Slammer
SQL Slammer is a virus that greatly affected banks and caused Internet speed to lag significantly across the globe. SQL Slammer caused an estimated $750 million in damages in 2003, and affected 200,000 computers worldwide.

8-Nimda
Nimda is one of the Internet’s most widespread viruses and among the costliest as well. The virus caused $635 million worth of damages in 2001 and caused Internet browsing time to slow significantly. Additionally, it could affect a user’s email account and send out a read-me file to all contacts listed in the email address book. The virus caused traffic and Internet speeds to slowdown.

9-Sasser
Sasser created quite a bit of trouble in 2004 when it piled up $500 million in damages, devastated the British Coast Guard mapping system and caused numerous canceled flights. The creator of Sasser was identified as a teenager from Germany, and was quickly apprehended when one of his “friends” turned him in for a $250,000 bounty posted by Microsoft

10-The Bottom Line
While the Internet can be a wonderful resource for doing everything from communicating with friends and colleagues to checking your bank statement, it is not necessarily the safest of places to perform such transactions when viruses are lurking in the midst. Protect yourself and your computer with quality anti-virus software, and continue to browse safely on the Internet.

1-The Morris Worm

On November 2, 1988, the worm was released and within 24 hours, an estimated 10 percent of computers connected to the internet were affected. The malware slowed down thousands of systems by creating files in temporary folders in an effort to replicate itself.

2-ILOVEYOU

It came with the attachment, “LOVE-LETTER-FOR-YOU.txt.vbs”. Once opened, it would send itself to everyone in the Outlook address book, making this one of the fastest-spreading viruses at the time.

3-MyDoom

MyDoom could further stop a device from running updates to security software!

The most concerning part of the virus was its ability to open a back-door vulnerability in systems for hackers to exploit. Some of these back-doors remain open.

4-WannaCry
It was particularly cruel: using a back-door exploitation in Microsoft Windows, it would encrypt all data on the device and hold your files to ransom,Once infected, a computer’s screen locks, showing a red warning and two countdowns, one until the ransom demand would rise and the other until files would be permanently deleted.

5-CryptoLocker

Released in September 2013, CryptoLocker spread through email attachments and encrypted the user’s files so that they couldn’t access them.

The hackers then sent a decryption key in return for a sum of money,

6-Storm Worm

Storm Worm was a particularly vicious virus that made the rounds in 2006 with a subject line of ‘230 dead as storm batters Europe’. Intrigued, people would open the email and click on a link to the news story and that’s when the problems started.

Storm Worm was a Trojan horse that infected computers, sometimes turning them into zombies or bots to continue the spread of the virus and to send a huge amount of spam mail.

7-Slammer

While most of the malware on this list strictly hit computers, Slammer was created with broader ambitions. Slammer is the kind of virus that makes it into films, as only a few minutes after infecting its first victim, it was doubling itself every few seconds. 15 minutes in and Slammer had infected half of the servers that essentially ran the internet.

8-Stuxnet

Stuxnet is easily the scariest virus on the list as it was built by government engineers in the US with the intention of obstructing nukes from being built in Iran.
Stuxnet spread by a USB thumb drive and targeted software controlling a facility in Iran that held uranium. The virus was so effective it caused their centrifuges to self-destruct, setting Iran’s nuclear development back and costing a lot of money.

In this list, we will highlight some of the worst and notorious computer viruses that have caused a lot of damage in real life. And since people usually equate general malware like worms and trojan horses as viruses, we’re including them as well. These malware have caused tremendous harm, amounting to billions of dollars and disrupting critical real life infrastructure. Here are the 10 most famous and malicious computer viruses.
1. ILOVEYOU
The ILOVEYOU virus is considered one of the most virulent computer virus ever created and it’s not hard to see why. The virus managed to wreck havoc on computer systems all over the world, causing damages totaling in at an estimate of $10 billion. 10% of the world’s Internet-connected computers were believed to have been infected. It was so bad that governments and large corporations took their mailing system offline to prevent infection.
The virus was created by two Filipino programers, Reonel Ramones and Onel de Guzman. What it did was use social engineering to get people to click on the attachment; in this case, a love confession. The attachment was actually a script that poses as a TXT file, due to Windows at the time hiding the actual extension of the file. Once clicked, it will send itself to everyone in the user’s mailing list and proceed to overwrite files with itself, making the computer unbootable. The two were never charged, as there were no laws about malware. This led to the enactment of the E-Commerce Law to address the problem.

2. Code Red
Code Red first surfaced on 2001 and was discovered by two eEye Digital Security employees. It was named Code Red because the the pair were drinking Code Red Mountain Dew at the time of discovery. The worm targeted computers with Microsoft IIS web server installed, exploiting a buffer overflow problem in the system. It leaves very little trace on the hard disk as it is able to run entirely on memory, with a size of 3,569 bytes. Once infected, it will proceed to make a hundred copies of itself but due to a bug in the programming, it will duplicate even more and ends up eating a lot of the systems resources.
It will then launch a denial of service attack on several IP address, famous among them the website of the White House. It also allows backdoor access to the server, allowing for remote access to the machine. The most memorable symptom is the message it leaves behind on affected web pages, “Hacked By Chinese!”, which has become a meme itself. A patch was later released and it was estimate that it caused $2 billion in lost productivity. A total of 1-2 million servers were affected, which is amazing when you consider there were 6 million IIS servers at the time.
3. Melissa
Named after an exotic dancer from Florida, it was created by David L. Smith in 1999. It started as an infected Word document that was posted up on the alt.sex usenet group, claiming to be a list of passwords for pornographic sites. This got people curious and when it was downloaded and opened, it would trigger the macro inside and unleash its payload. The virus will mail itself to the top 50 people in the user’s email address book and this caused an increase of email traffic, disrupting the email services of governments and corporations. It also sometimes corrupted documents by inserting a Simpsons reference into them.
Smith was eventually caught when they traced the Word document to him. The file was uploaded using a stolen AOL account and with their help, law enforcement was able to arrest him less than a week since the outbreak began. He cooperated with the FBI in capturing other virus creators, famous among them the creator of the Anna Kournikova virus. For his cooperation, he served only 20 months and paid a fine of $5000 of his 10 year sentence. The virus reportedly caused $80 million in damages.
4. Sasser
A Windows worm first discovered in 2004, it was created by computer science student Sven Jaschan, who also created the Netsky worm. While the payload itself may be seen as simply annoying (it slows down and crashes the computer, while making it hard to reset without cutting the power), the effects were incredibly disruptive, with millions of computers being infected, and important, critical infrastructure affected. The worm took advantage of a buffer overflow vulnerability in Local Security Authority Subsystem Service (LSASS), which controls the security policy of local accounts causing crashes to the computer. It will also use the system resources to propagate itself to other machines through the Internet and infect others automatically.
The effects of the virus were widespread as while the exploit was already patched, many computers haven’t updated. This led to more than a million infections, taking out critical infrastructures, such as airlines, news agencies, public transportation, hospitals, public transport, etc. Overall, the damage was estimated to have cost $18 billion. Jaschen was tried as a minor and received a 21 month suspended sentence.
5. Zeus
Zeus is a Trojan horse made to infect Windows computers so that it will perform various criminal tasks. The most common of these tasks are usually man-in-the-browser keylogging and form grabbing. The majority of computers were infected either through drive-by downloads or phishing scams. First identified in 2009, it managed to compromise thousands of FTP accounts and computers from large multinational corporations and banks such as Amazon, Oracle, Bank of America, Cisco, etc. Controllers of the Zeus botnet used it to steal the login credentials of social network, email and banking accounts.
In the US alone, it was estimated that more than 1 million computers were infected, with 25% in the US. The entire operation was sophisticated, involving people from around the world to act as money mules to smuggle and transfer cash to the ringleaders in Eastern Europe. About $70 million were stolen and in possession of the ring. 100 people were arrested in connection of the operation. In late 2010, the creator of Zeus announced his retirement but many experts believe this to be false.
6. Conficker
Also known as Downup or Downadup, Conficker is a worm of unknown authorship for Windows that made its first appearance in 2008. The name comes form the English word, configure and a German pejorative.It infects computers using flaws in the OS to create a botnet. The malware was able to infect more than 9 millions computers all around the world, affecting governments, businesses and individuals. It was one of the largest known worm infections to ever surface causing an estimate damage of $9 billion.
7. Stuxnet
8. Mydoom
9. CryptoLocker
10. Flashback

1-The Morris Worm

On November 2, 1988, the worm was released and within 24 hours, an estimated 10 percent of computers connected to the internet were affected. The malware slowed down thousands of systems by creating files in temporary folders in an effort to replicate itself.

2-ILOVEYOU

It came with the attachment, “LOVE-LETTER-FOR-YOU.txt.vbs”. Once opened, it would send itself to everyone in the Outlook address book, making this one of the fastest-spreading viruses at the time.

3-MyDoom

MyDoom could further stop a device from running updates to security software!

The most concerning part of the virus was its ability to open a back-door vulnerability in systems for hackers to exploit. Some of these back-doors remain open.

4-WannaCry
It was particularly cruel: using a back-door exploitation in Microsoft Windows, it would encrypt all data on the device and hold your files to ransom,Once infected, a computer’s screen locks, showing a red warning and two countdowns, one until the ransom demand would rise and the other until files would be permanently deleted.

5-CryptoLocker

Released in September 2013, CryptoLocker spread through email attachments and encrypted the user’s files so that they couldn’t access them.

The hackers then sent a decryption key in return for a sum of money,

6-Storm Worm
Storm Worm was a Trojan horse that infected computers, sometimes turning them into zombies or bots to continue the spread of the virus and to send a huge amount of spam mail.