Ever since the Dawn of the digital age hackers have been coding, all sorts of malicious software.
Some are just annoying pranks, while others are so disastrous.
They disrupt entire infrastructures and cause millions, if not billions of dollars in damages.
Join us, as we look at some of the most dangerous computer viruses of all time.
For convenience, we've included other malware, including worms and Trojan horses.
Number 10: Sobig This was a series of computer worms that infected
millions of computers throughout 2003. There were a total of six iterations of the
virus, each labelled with the letters A to F.
The sixth one, Sobig F held the record as the most transmitted virus in history.
Infecting up to a million compute systems within a single day,
The virus was engineered brilliantly to form mail servers into letting it through as a
legit non spam message. And upon opening, would send copies of itself
to the user's entire email list. Damages caused by Sobig is estimated to be
over $30 billion. The creators are still unknown and Microsoft
has offered $250,000 for info leading to their capture.
Number 9: I love you I love you, this romantically named virus
was created in 2000 by two Filipino programmers who used clever social engineering tactics
to get the virus to spread. The file “I love you” was a script disguised
as a normal txt file. That sounded like a confession from a secret
admirer, it blowed people's defences making them curious to know their secret Valentine.
But once opened, the file immediately sent copies of itself to the user's email contacts.
It would also proceed to overwrite files within itself, making the computers unbootable a
whopping 10% of the entire world's population got infected.
Wreaking havoc on systems worldwide causing 10$ billion in damages.
It was so bad that entire government and large companies had to take their mailing systems
offline to avoid getting infected. The programmers were never charged, as there
weren't laws on malware at the time. This has led to the enactment of the e-commerce
law to prevent similar incidents. Number 8: Storm Worm
Storm worm like many others, the storm worm propagated through email.
But instead of a file attachment, there would be a link to a website.
An interesting link at that with a catchy clickbait title, tempting gullible users towards
it, but when clicked nothing happened or so it seemed instead of destroying computer.
Storm worm aimed at taking over them, in the background the invisible Trojan horse would
allow hackers to remotely control the computers to do all sorts of stuff, including illegal
activities: such as stealing passwords, money and identity manipulation.
Storm worms started spreading in 2007 and within months drew into a wide network of
botnets from the millions of computers it controlled.
The programmers who still aren't caught would then sell the networks to other criminals.
Thankfully, the bot net is now wiped out, almost completely.
Number 7: Code Red Code red, this 2001 virus was discovered by
employees of a digital security company while drinking code red mountain Dew, hence its
name. It's spread through computers that use Microsoft’s
IIS web server and exploited the system’s buffer overflow problem.
It was extremely difficult to detect as its size was only about three kilobytes and ran
mostly on memory instead of disc space, once activated, it would replicate itself like
crazy. And eat up a lot of system resources.
Code red gained infamy when it managed to infect the white house's server and put down
the U S government's website, leaving behind a message saying hacked by Chinese, something
that grew into a popular meme. It's unlikely, the Chinese were really behind
it. Although no culprits were ever named, a patch
was released fixing the problem. But 2$ billion in productivity had already
been lost. The virus managed to affect 2 million servers.
About a third of all IIS servers at the time. Number 6: Slammer
Slammer, on the 25th of January, 2003, the entire internet broke down in South Korea
for 12 hours. The virus also affected other things around
the globe, such as airlines and bank ATM's. Connections either stopped completely or became
extremely slow even for 2003 standards. All this was caused by slammer, a worm that
specifically targeted Microsoft SQL servers by taking advantage of a bug present in the
software. What seemed like an ordinary request for information
was actually a code written to send out more copies of the worm to others severs.
It grew incredibly fast, doubling in size every eight seconds.
Millions of servers got infected before it was finally stopped causing 1.2$ billion in
damage. The people behind it were never caught.
And Microsoft had actually released the patch to fix the bug much earlier before the virus
spread, but many just hadn't installed it yet.
Number 5: Melissa Melissa, this one appeared quite early back
in 1999. And it was the first ever mass mailing macro
virus for the new internet age. Created by David Smith and named after a stripper,
he knew from Florida. The Melissa was spread through emails with
an attachment by the name list.doc. It was accompanied by a short note saying
here is the documents you asked for, don't show anyone else.
Like the, I love you. It depended on people's curiosities to get them clicking.
And boy did it work! Once the attachments file is clicked, it would replicate and send
itself to the user's email contact and would sometimes corrupt documents by inserting quotes
from the cartoon character, Bart Simpson. The FBI managed to trace the file back to
its creator and Smith was arrested within a week of the outbreak.
He later cooperated with law enforcement in capturing other hackers and malware creators,
enabling him to get a reduced sentence of only 20 months and a fine of 5,000$.
The Melissa virus was the fastest virus of its time causing 80 million$ in damages.
Number 4: Sasser Sasser in 2004, 18-year-old programmers, Sven
Jaschan created Sasser, a worm that primarily targeted windows.
The worm itself didn't do much other than annoyingly, slow down and crash computers,
but collectively the results were incredibly disruptive.
Millions of computers worldwide got infected. Including critical infrastructures, such as
public transport airlines and hospitals. Unlike other viruses, Sasser didn't spread
through email. Instead, it randomly scanned vulnerable systems
and instructed them to download the virus. It then attacked the local security authority
subsystem service causing the systems to crash. 18 million$ of damage was recorded.
Jaschan was caught, but as a minor got off with the light sentence.
Number 3: Mydoom My Doom in 2004, my doom took, I love you's
place as the fastest growing email worm. It was discovered by a McAfee employee in
2004. Who named it based on the line, “my dumb”
present in the program's code. Which meant “my domain”, but adding that
extra, oh, just made it sound a lot cooler. The creator who still hasn't been caught is
believed to have been paid to create the virus in order to attack large tech companies.
The worms spreads itself by deceiving email users by appearing as an error message that
reads mail transaction failed. But upon clicking the message, the firewall
sends itself to the user's email contacts and copies itself to any PTP programs folder
to propagate itself through that network. This results in a back door being opened that
allows a remote access. My doom is still somewhat active today in
other forms and has caused upwards of 38 billion$ in damages.
Number 2: Mebroot Mebroot, this is a sophisticated Trojan horse
that started spreading around 2007. The way mebroot works is by infecting your
computer. As you visit some malicious websites, it would
then overwrite your master reboot record, enabling it to tell your computer what to
do upon start-up. Which in this case is to connect to its partner
in crime, Torpig. Torpig would then proceed to look silently
in your browser, keeping track of all the information you type in, your passwords, your
account number and every website you visit. Within a year, mebroot torpig managed to steal
info from over half a million bank accounts. The virus creators are still at large.
Number 1: Leap Leap, many apple fanboys claim that Mac computers
are impenetrable to viruses, by running a tightly closed system.
Apple has managed to protect its software, preventing hackers from getting into their
system as easily as they could with normal PC’s.
But the myth of their invincibility was shattered with the debut of leap-A in 2006, also known
as “Oomp-A” this virus utilized Apple’s ichat instant messaging program.
Once a Mac is infected, it will send a message to other user’s in the ichats, contact list.
In order to propagate itself, the payload isn't much though, as it's only prevents an
infected application. However, it's shown the world that Macs are
not as impenetrable as we thought, paving a way for hackers to create more customized
viruses in the future. Have you been victim to any viruses or are
you one to shy away from dodgy emails? Let us know in the comments below.