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10 Worst Computer Viruses Ever Created

February 2, 2020

Computers and the internet have opened up
the world in ways previously thought to be impossible. But, as a wise uncle once said
with great power comes great responsibility. Sadly, many like to abuse this power and as
a result a number of nasty computer viruses have been created with only malicious intentions,
so join us as we count 10 of the worst computer viruses ever created.
Melissa Melissa is a computer virus based on a Microsoft
Word macro. It was designed so that it could spread through e-mail messages and cause havoc
on both government and private sector networks. In short, the Melissa virus tempts recipients
into opening a document with an e-mail message along the lines of “Here’s that document
you asked for, don’t show it to anyone else”. Once the user opens the document, the virus
is replicated and sends itself out to another 50 users, chosen from the top contacts in
the recipient’s address book. Melissa spread ferociously throughout the world after it
was released, the increase in e-mail traffic from this alone forced some companies to discontinue
their e-mail services until the virus was contained. The created of Melissa, David L.
Smith was sentenced to a 20 months in jail, was given a $5,000 fine and he was forbidden
to access computer networks without court authorization.
ILOVEYOU Only 1 year after the Melissa virus reigned
terror upon the internet, a new threat entered the game from the Philippines, this time in
the form of a worm with the name of ILOVEYOU. This virus travelled by e-mail just like Melissa,
but the message instead was a love letter from a secret admirer. Upon opening the attachment,
many bad things happened. According to McAfee, the ILOVEYOU virus had a number of abilities
such as copying itself and hiding the copies in several folders on the victim’s hard
drive, adding new files to the computer’s registry keys, replacing files with copies
of itself and sending itself through chat clients as well as e-mail. So who made this
destructive menace? Some think it was a chap called Onel de Guzman, but this was never
confirmed and he was never convicted. According to some sources, the virus caused over $10
billion in damages. SQL Slammer
The SQL Slammer, also known as Sapphire hit in late January 2003. It brought down many
important systems including The Bank of America’s ATM service, Continental Airline’s ticketing
and check-in systems and even caused the city of Seattle’s 911 service to suffer outages.
Estimates put the damages to be around $1 billion before the virus was stopped. This
is partly because of how rapidly it spread. Only minutes after infecting its first server,
Slammer was doubling it’s infected victims every few seconds.
The Klez Virus The Klez Virus debuted in late 2001 and had
a number of variations that scoured the internet. The original iteration was similar to the
Melissa virus in that it could send itself to people in the victim’s address book.
However, shortly after it’ introduction, hackers modified the virus to not only send
itself to contacts, but to also use a different name from the contact list and pretend to
be the sender. This is called spoofing, the e-mail appears to come from one source when
in fact it comes from another. It makes it very difficult to stop the spam e-mails since
the recipient doesn’t know where the e-mails are actually coming from. It also doesn’t
help to block the sender’s address since this is not the proper address. Finally, recipients
were more likely to trust the contents of the e-mail since it was coming from somebody
they knew. MyDoom
MyDoom was another worm that created a backdoor in operating systems, allowing remote users
to control the machine. The initial outbreak of MyDoom occurred in February 2004 had 2
stages. Stage 1 caused the virus to begin a denial of service attack and Stage 2 stopped
the virus from distributing itself any further. Later that same year, a second outbreak occurred
that caused many problems for search engine providers since the MyDoom virus would send
search requests to the search enginers using e-mail addresses it found or already knew.
This caused millions of search requests to hit search engines like Google and it resulted
in their services being slowed down or in some cases, it even caused them to crash.
According to MessageLabs, one in every 12 e-mails carried MyDoom at one time.
Nimda Apparently 2001 was hot year for nasty viruses.
Nimda was another worm that spread rapidly through the internet from the moment it launched.
According to TruSecure’s CTO, Peter Tippett, it only took 22 minutes for Nimda from the
moment it was launched to top the list of reported attacks. Due to the release date,
exactly one week after the attacks on the World Trade Center and Pentagon, some media
quickly began speculating a link between the virus and Al Qaeda, though this theory ended
up proving unfounded. It’s main priority was to attack Internet Servers and to destroy
Internet traffic through e-mails, opening network shares, browsing unsecured websites
and exploiting Microsoft IIS vulnerabilities. Code Red and Code Red II
More worms. These surfaced in the summer of 2001. Both worms exploited a vulnerability
within the operating system of Windows 2000 and Windows NT. In simple terms, the worms
would overload the operating system with information, causing the machines to crash. However, a
Windows 2000 machine infected by the Code Red II worm brought an even worse result.
The machine would no longer obey commands from the user since the worm allowed a remote
user to access and control the machine, allowing them to not only access information but they
could even use the infected machine to commit crimes. This brought a second layer of issues
for the victims of the worm, since they may also be accused of causing crimes they didn’t
actually commit. Windows NT machines were also vulnerable, but to a much lesser extent.
Microsoft eventually addressed the issues with a patch, stopping the worm from being
able to infect any more machines. Sasser and Netsky
Sasser and Netsky behaved in different ways but similarities in the code allowed authorities
to track the viruses back to their origin, a 17 year old German named Sven Jaschan. The
Sasser worm used a Microsoft vulnerability to infect systems. Once infected, searched
for other vulnerable systems and instructed them to download the virus. In addition to
this, it manipulated the operating system to make it difficult to shut down the system
without pulling power from the machine. Netsky moved through e-mails by spoofing itself and
caused denial of service attacks on systems. Sophos believed that Netsky at one time accounted
for a quarter of all computer viruses on the internet. Sven didn’t spend any time in
jail. He was given a year and nine months of probation because he was under 18 at the
time of his conviction. Storm Worm
It was late 2006 when Storm Worm was first identified. It got its name from the message
subject in the e-mail, which read “230 dead as storm batters Europe”. It was a Trojan
horse program that had many versions. Some of them would turn computers into bots or
zombies, and would be used to send further spam mail across the Internet. The people
behind Storm Worm were smart, and would re-name the message subjects to match recent news.
For example, just before the 2008 Beijing Olympics, the subjects were changed to things
like “China’s deadliest ever earthquake”. At it’s peak Storm Worm accounted for around
8% of all infected machines. It may still be around today but to a much lesser extent,
and as long as you keep your antivirus updated and remain cautious when opening attachments,
you’ll likely be just fine. Cryptolocker
I myself used to work on an IT Helpdesk not long ago, and I had the misfortune of coming
across this terrible thing. Cryptolocker is a ransomware, meaning that it’s designed
to block access to files or computers until a sum of money is paid, and boy was it effective.
It surfaced in late 2013 via e-mail attachments. When the files were activated, it would encrypt
pretty much any files it could find on both local and network drives. This was bad news
for companies because as long as the infected person had a network share mounted at the
time of infection, Cryptolocker could jump to the server and infect everything there
as well. Once a machine was infected, it would display a message offering to decrypt the
data for a certain amount. From cases I came across it was often around $400.
What made Cryptolocker even more infuriating was the fact that it was really easy to remove
from a computer, but this didn’t help get the data back since it was already encrypted.
Reportedly Cryptolocker extorted a sum in excess of $3 million before it was brought
to a halt in the summer of 2014.


  • Reply Jesus Christ June 2, 2017 at 8:04 am

    lol video.exe

  • Reply destroy Doodnath June 2, 2017 at 11:55 pm

    my old computer had a virus call geekbuddy

  • Reply dking2004 June 5, 2017 at 6:09 am

    Memz trojan

  • Reply elizauwu June 7, 2017 at 3:31 am

    where da memz at

  • Reply After Game June 8, 2017 at 10:57 pm

    why do people even create viruses

  • Reply EAS Pennsylvania June 10, 2017 at 4:12 pm

    1:56 Help. John Doe is there. HE'S GONNA HACK ME NEXT!!!!!

  • Reply ok no June 11, 2017 at 7:00 pm

    ( HAHAHAAHAHAHAHAHAHAHAHAHHAAH⊙¡⊙¡⊙¡⊙¡⊙¡⊙¡⊙¡⊙¡⊙⊙¡⊙¡⊙¡⊙¡⊙¡⊙¡⊙¡⊙¡⊙¡⊙¡SKSK)

  • Reply Andy June 13, 2017 at 8:33 pm


  • Reply Ivan Felisario June 14, 2017 at 5:47 pm

    netsky?? bad name why not SkyNet

  • Reply trookle June 15, 2017 at 11:33 am


  • Reply Somer Kemble June 16, 2017 at 3:17 am


  • Reply Somer Kemble June 16, 2017 at 3:18 am

    why ant the saw virus on here

  • Reply Bluecatte June 16, 2017 at 2:23 pm


  • Reply TurkeyBoy55 June 17, 2017 at 11:40 pm


  • Reply YOLI NKIV June 18, 2017 at 1:23 pm

    number 8 came the year i was born

  • Reply PenguinStar42 June 18, 2017 at 6:19 pm


  • Reply Andre01248 on Roblox June 21, 2017 at 7:03 pm


  • Reply _DarkPlayz_ w June 23, 2017 at 6:02 pm

    1:53 John Doe? seems familier…. roblox plays in the backround hmm who could it be

  • Reply NekoGod June 26, 2017 at 12:54 pm

    if i get 100 likes ill make a virus and make it spam conputers

  • Reply NekoGod June 26, 2017 at 12:56 pm

    i wish i was born during 2001 or any time a virus attack happened

  • Reply Hotwire Youth June 27, 2017 at 8:29 am

    Just remember I love you 😉

  • Reply Ólavur Tyrni June 27, 2017 at 9:29 pm

    These Were also in be amazed's video Called top 10 Worst viruses

  • Reply Maj mac June 29, 2017 at 8:56 am

    i have iloveyouvirus on my old disc

  • Reply Paper Mario July 4, 2017 at 2:24 pm

    What about MEMZ Trojan

  • Reply Midget GamingYT July 10, 2017 at 7:36 pm

    Number nine OMG John doe roblox John doe real John doe??!!!!

  • Reply Nightfall_gamer323 July 12, 2017 at 1:55 pm


  • Reply Preston103 July 15, 2017 at 5:08 pm

    Jon doe is PURE EVIL

  • Reply Ac3dan July 16, 2017 at 2:48 am

    at 1:56 why does it say john doe a.k.a roblox ghost??

  • Reply EmilyAuto July 16, 2017 at 6:39 pm

    1:48 To: JOHN DOE From: JOHN DOE … Wait, L-Like the HACKER John doe? I-In Roblox??

  • Reply ZachStudios July 18, 2017 at 2:43 am

    was MEMZ just created for fun basically?

  • Reply Maximus2 Vazquez July 19, 2017 at 12:07 am

    What about MEMZ?! It's the most destructive one out there but not really but it is so ehhh

  • Reply theDragoon007 July 21, 2017 at 6:06 am

    this reminds me when i love to hack emais and i sen messages with insults as fuck you and the people start to fight :v

  • Reply sonic gaming July 22, 2017 at 10:54 pm

    Fuck deez boys

  • Reply xx_.tylerrr._xx July 23, 2017 at 3:10 am

    did you forget about memz

  • Reply Toxic Bullet July 24, 2017 at 2:40 am

    who else noticed the second ones "from" position says john doe. that name is being used a lot of times

  • Reply FC Porto Mundo July 26, 2017 at 11:59 pm

    Don't bring uncle ben into this

  • Reply Rosemarie Menguito July 28, 2017 at 12:39 am


  • Reply Rosemarie Menguito July 28, 2017 at 12:40 am

    ILOVEYOU Virus

  • Reply Ace Johnston July 30, 2017 at 3:08 am

    make a new one wannacry

  • Reply Reed Preston YT July 31, 2017 at 6:05 am

    There is a dangerous virus that people don't know that much it's called memz it will change the look of ur desktop and do the double of ur desktop it's not pretty

  • Reply Ahamed July 31, 2017 at 8:42 pm

    i have the Redirect virus

  • Reply Calvin Thomas August 1, 2017 at 1:59 am

    Fun fact, the name Code Red comes from the kind of Mountain Dew.

  • Reply kurb August 1, 2017 at 7:26 pm

    1. Memz.
    2. Bonzibuddy
    3. YouAreAnIdiot
    4. Free minecraft hax

  • Reply Momo August 3, 2017 at 5:17 am

    The Melissa virus would not be able to send to any of my contacts because I have none. Why do I have no contacts, you ask? Well, I have no friends 🙃😭😢
    I also like my own comment because that's how lonely I am

  • Reply BitterBatter August 4, 2017 at 12:01 pm

    OMG John Doe the hacker in roblox that i think didn't come i guess😕😕😕😕
    Edit: IDK

  • Reply Blue W0lf August 4, 2017 at 7:49 pm

    I once had a bad pop-up virus. It doesn't sound that bad, but I had to reset my computer.

  • Reply Lea August 7, 2017 at 6:01 pm

    yea i got my own virus that does nothing 😀

  • Reply FSThunder August 7, 2017 at 7:07 pm

    Wow. This gave me goosebumps…

  • Reply Sarah August 7, 2017 at 10:01 pm

    Guys look at the from on 1:59 its john doe from roblox

  • Reply Joshua Atkeson August 13, 2017 at 3:15 am

    i thought MEMZ was bad

  • Reply arxcylide August 18, 2017 at 7:17 am

    i am scared to download skype.
    oh no so scared

  • Reply Mishu • Gaming August 18, 2017 at 9:01 pm

    I can make a deadly virus if anybody wants to get revenge or something. It's free ..

  • Reply Lucario 1829 August 21, 2017 at 4:40 am

    Listening to the Melissa one was awful for me. Me: Gets distracted. Video: Melissa. Me: What? Oh, it's the vid.

  • Reply DanPanKing August 23, 2017 at 3:47 pm

    Who else installed anti virus after this

  • Reply Exility Snowy August 24, 2017 at 10:02 pm

    What ILOVEYOU ??

  • Reply Dancing Egg August 28, 2017 at 3:01 am

    I think I'm gonna have nightmares after I watch this

  • Reply Rubick August 28, 2017 at 1:44 pm

    what that LOVELETTER does? It's not that destructible

  • Reply ShadowFall 1976 August 28, 2017 at 8:07 pm

    where is wanacry

  • Reply CrocX 2 August 28, 2017 at 11:06 pm

    I did Memez tivor

  • Reply Nevla September 1, 2017 at 6:36 am

    3:46 great job sharing someones IP address dumbass….

  • Reply Dinidu Samaranayake September 5, 2017 at 3:52 pm

    Oh a virus 7 days after 9/11
    Did Rockstar get affected? IS GTA3 A VIRUS

  • Reply Dinidu Samaranayake September 5, 2017 at 3:55 pm

    Man the people who caused these viruses should be KILLED OUT IN PUBLIC

  • Reply si lo September 21, 2017 at 11:52 am

    MEMS was made on perpose so a youtuber could use it for a video. It isn't a virus that you get from a website without you knowing it has a download saying "get MEMS" it was made on perpose

  • Reply Epic Lokvanji September 24, 2017 at 8:48 am

    NO MEMZ ???

  • Reply zketchh September 24, 2017 at 8:29 pm

    Just to clear everything, MEMZ wasnt in this because MEMZ wasnt really a virus that could purposely hurt you. MEMZ was actually a joke and you, the owner of the PC, get to use the virus if you just want to. The owner of the virus even made a pop-up that says this virus will fu%& up your computer, and asks if youre sure you want to open it.

    Just to clear it up.

  • Reply Puglover 672 October 1, 2017 at 6:54 am

    Omg I already knew all of these

  • Reply laura Berrie October 10, 2017 at 4:40 pm

    For the last one, go to a computer shop, lycamobile, etc then ask them to check the computer. you might get a new one or get it repaired.

  • Reply XxGitRektM8xX October 22, 2017 at 9:49 am


  • Reply p_ October 25, 2017 at 8:13 am

    What if there’s a virus called 110000000011110011010100101000101010101011100

  • Reply Miriam Morello October 28, 2017 at 6:02 pm


  • Reply El compa fenicz October 29, 2017 at 11:35 pm

    Pro Steps On How not to download a virus

    1. Don't download a virus

  • Reply Xasmanius Völk November 27, 2017 at 12:54 am

    Cmon, you can open half of the viruses with notepad and read what they to. Why people are that stupid?

  • Reply The Magical Dog December 16, 2017 at 7:25 pm

    John Doe was here

  • Reply RUTH FLORES December 20, 2017 at 5:51 am

    Did you know the blue chrome is a virus like this comment if it's a virus

  • Reply Sea Gall December 24, 2017 at 5:23 am

    Darn it I’m not using email anymore!

  • Reply Joel De La Garza December 25, 2017 at 6:37 am


  • Reply Joel De La Garza December 25, 2017 at 6:41 am


  • Reply Jaromir Teope January 1, 2018 at 2:29 am

    Is MacAfee antivirus not a form of Bakasoftware? My computer uses MacAfee antivirus and doesn't want viruses.

  • Reply GROG PROG January 16, 2018 at 3:07 pm

    Where's memz?

  • Reply Memetry gamer Also YGS every sat/sun January 26, 2018 at 8:21 pm

    Dude we’res Memz Mr

  • Reply FoxGaming February 20, 2018 at 7:33 am

    Yes sadly it broke my 20000 dollar laptop yep 20000 dollar it cant be fixed so i broke it sadly rip my life

  • Reply Sunwolfangel323 OFFICAL March 16, 2018 at 2:23 pm

    Nimda sounds like Linda

  • Reply ninjanerd9812 March 17, 2018 at 2:52 pm

    I had sasser on my windows xp

  • Reply ninjanerd9812 March 17, 2018 at 2:53 pm

    but I use windows 10

  • Reply Doggo March 20, 2018 at 1:26 pm

    OMG guys if you know Roblox second player created is John Doe and the vures ILOVEYOU is from John Doe Have a Close Look

  • Reply CashioKing March 30, 2018 at 1:59 pm

    netsky, skynet.. terminator… hmm

  • Reply PuffTV April 22, 2018 at 12:39 pm

    What about killbot.exe

  • Reply vortex effect June 4, 2018 at 10:11 am

    scorpian virus!!!

  • Reply Call me whatever you want June 4, 2018 at 11:48 am

    1:54 wait john doe dont tell me that we are going back to roblox myths

  • Reply Aiden Nonya June 17, 2018 at 11:54 pm

    I've had storm worm before

  • Reply tfeL July 3, 2018 at 9:37 pm

    what about Wanna cry?

  • Reply Joan Loveee August 10, 2018 at 11:08 pm

    Anyone caught that "John Doe"??

  • Reply Kenneth Williams September 15, 2018 at 2:32 am

    bonzibuddy should be on here

  • Reply tfeL November 25, 2018 at 7:09 pm

    By the way what about wannacry

  • Reply Chris Hagemarcou January 13, 2019 at 12:44 am

    Where's the MEMZ Trojan?

  • Reply Calebt1130 YT_btw April 22, 2019 at 3:41 am

    I create computer viruses for fun haven’t sent any of them to anyone yet check out my latest vid if you want to find out how to do it

  • Reply GD Redmzis June 21, 2019 at 11:03 am

    You forgot SOBIG

  • Reply F A D E July 19, 2019 at 7:35 pm

    Won't work on my i don't have friends

  • Reply Inparsian August 13, 2019 at 12:36 am

    your voice lmao

  • Reply Commander Gio January 18, 2020 at 10:07 am

    The number 1 worst virus should be MYDOOM

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