Want to know about the worst computer viruses ever and how they wreak havoc on your system?
Then stay tuned! Because in this video, we will cover 11 most dangerous computer viruses
in the world. These days, having an excellent antivirus
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down below. So hurry up before the sale ends. Now, lets begin.
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Without your support, we may not be able to continue making these videos. So please hit
the like button right now. A computer virus is a software program that
can corrupt or destroy the data stored on an infected machine. As if that's not enough,
a virus can also duplicate itself and evolve constantly.
When you connect to the internet, it opens a gateway to computer viruses. Simply anything
and everything you do on the internet may present an opportunity for a computer virus
to find you like visiting malicious websites, opening spam emails, downloading games, songs,
or movies. A computer sends out many different signals
when infected with a virus, such as erratic behavior, frequent data loss, and system crashes.
Make sure you are aware enough to catch those signals when that happens.
Since the very first computer virus in 1971, called the "Creeper system," thousands of
viruses have continued to infect the computers. Today, thousands of new virus samples are
released in just a single day. Not just individuals, but many reputed companies
lost a lot of money in virus damages, which means there is enough possibility for you
to be threatened if your system is not properly protected.
In this video, we've compiled and explained eleven most dangerous computer viruses notorious
for jamming and infecting computers and damaging the sensitive data.
We will cover these in the reverse order. At number 11, we have Melissa Virus.
Named after a foreign dancer in Florida, Melissa virus was the brainchild of a programmer David
Lee Smith who created the virus in 1999 to spread it through email messages containing
infected word documents as attachments. He made the subject of the emails attractive
so that the victims couldn't ignore it easily and opened the infected document. The email
claimed that the attachment contained dozens of free passwords to free adult content websites.
As soon as a user downloaded the document, the Melissa virus would catch the top 50 email
contacts from the victim's account, who would then receive a copy of the same malicious
email. That's how the virus multiplied and kept going around the internet.
Even though Melissa virus did not steal victims' personal information and the cybersecurity
experts were soon able to contain the virus, the damage it caused cannot be underestimated.
Records say that this virus infected at least 100,000 computers and 300 organizations, causing
$1.1 billion worth of damages worldwide. Even the government agencies could not protect
their systems from this notorious virus. Millions of infected emails created unnecessary
traffic on the internet, and ultimately the running speed of the internet became very
slow. This led many victim companies to cease their email programs until they resolved the
problem.
At Number 10, we have Stuxnet virus. Stuxnet was a malicious multi-part worm that
was developed in 2005 but first became public in 2010. Stuxnet travelled around mostly through
USB sticks and Microsoft Windows computers. This virus is considered one of the most dangerous
viruses mainly because it was aimed at infecting industrial and energy-producing facilities,
especially Iran's nuclear plants, by seizing full control of the equipment automation software.
Stuxnet received much media attention for its capability to cripple computer hardware.
But the virus grabbed outstanding media attention after the world recognized it as a joint creation
of the U.S. National Security Agency, the CIA, and Israeli intelligence.
Stuxnet had three modules called, the worm, the link file, and the rootkit. The worm implemented
the routine related to the main component of the attack, which executed the malicious
activity. The link file performed the task of generating
the propagated copies of the worm automatically. Whereas the rootkit was responsible for hiding
the malicious files in order to avoid detection by antivirus programs.
Stuxnet is believed to have damaged almost one-fifth of Iran's nuclear centrifuges, further
infecting over 200,000 computers worldwide. But Iran probably received the biggest damage
wreaked by the virus, as 60% of the infected systems were in Iran.
Next up is MyDoom at Number 9. MyDoom is also called W32.MyDoom@mm, which
was the very first version of the worm. The virus was initially sighted on 26th January
2004, but research has shown that it is still active.
MyDoom is believed to originate from Russia, but the author is still unknown. The entire
program was written in the C++ language, and it only affected Microsoft Windows computers.
MyDoom spreads the same way as Melissa virus and via peer to peer networks. Once it downloads
onto a system, it creates a backdoor in the operating system for other malicious software
to creep in. Normally the infected email contains some
kind of transmission error having subject lines such as "Error," "Mail Delivery System,"
"Test," or "Mail Transaction Failed." It also uses different languages to avoid the chance
that the reader purposely ignores opening the message.
MyDoom is recognized as the fastest spreading email-based worm ever. This nasty virus has
already cost the world $38 billion in damages and still continues, which has earned it the
reputation of being the most devastating virus to date.
A fun fact about MyDoom is that the virus even has a song dedicated to it by the famous
British IDM musician named Aphex Twin, who has a few song numbers on different viruses
and malware. Moving on to number 8, we have the ILOVEYOU
virus. ILOVEYOU was a computer virus or worm with
the capability to replicate itself. "Lovebug and Love Letter for you" are some of the other
names given to this malicious virus. It originated in the Philippines and affected over 10 million
Windows PCs worldwide. ILOVEYOU virus used websites and file sharing
methods to spread around, particularly email messages. While emails were the quickest way
for the virus to find its victims, these emails looked like a love letter from a secret admirer.
The email would usually contain an attachment that carried the actual virus. Once opened,
the virus re-sent the email to every contact in the victim's Microsoft Outlook address
book and then damaged every JPEG and MP3 file as well as a few other file formats.
In addition to replicating itself, the virus also hid copies of its code in the victim's
hard disk and added new files to the registry key, making it hard to get rid of and just
as much annoying. The virus affected over 500,000 systems in
the year 2000 and caused over $15 billion worth of damages, out of which $5.5 billion
were produced in the first week alone. The virus is believed to have affected nearly
10% of the world's computers. The interesting thing is that even after 20
years of its creation, the virus is still being used in one form or another because
amazingly, it still works.
Number 7 is the Nimda virus. Nimda is considered one of the most dangerous
and fastest-growing computer viruses. Records say that it took only 22 minutes for Nimda
to come to the top of the recorded attacks from the moment it initially hit the internet.
Nimda, which is "admin" spelled backward, was initially spotted on 18th September 2001.
It was developed in China and written in the C++ language. Email messages, open network
shares, compromised websites were some of the ways the virus used to spread. That's
how it became one of the fastest spreading computer viruses.
The ultimate target of Nimda was not just to attack the individual users but the internet
servers and bring the internet traffic to a crawl. Nimda created a backdoor in the user's
operating system, giving the attacker permission to control the system functions to the extent
the original user was allowed. For example, if you were a user with limited
access to the system, then the attacker could only make changes within the same limitations.
But unfortunately, if you were the administrator of the system, your entire machine was at
the attacker's disposal.
Up next, we have Fleeceware at number 6. Usually, people feel safe in downloading apps
from the official app stores such as Google Play Store and the App Store. However, it
does not mean that it completely avoids the chance of you installing a malicious app on
your phone. The Fleeceware is a bit different from other
viruses; it is kind of a malicious app you install into your phone. Fleeceware does not
steal or harm your information. It works like a normal advertised app but with excessive
hidden subscription charges. Here's how you can know if an app is a Fleeceware.
If you have to pay for a common featured app such as a photo editing app or a horoscope
app, then that is indeed a Fleeceware. These apps will usually start charging you after
a brief trial period even after you have uninstalled the app.
Fleeceware developers normally use zombie accounts to boost their reviews and downloads
so the users will easily fall prey to such apps.
At Number 5, we have Fake Windows Updates or Hidden Ransomware.
Once again, spam emails are the culprit here. The attackers send malicious emails with an
attachment disguised as a JPG file sent by Microsoft itself, asking users to update their
operating system. The ransomware starts installing to your computer
as you follow the action stated in the email. Technical users are aware that Microsoft does
not send updates through emails. But non-technical users can easily become a victim to these
spam emails. Emails of this kind normally include two subject
lines and one sentence starting with two capital letters in its first word.
The ransomware contained in the email was named "Cyborg," which encrypts the files on
a PC and then displays a ransom note called "Cyborg_DECRYPT.txt" on the desktop asking
for 500 dollars as ransom money. The virus also leaves behind a copy of itself
called bot.exe, which hides at the root of the infected drive.
Beware of such update notifications in your inbox. You should know that Windows does not
send updates to users' inbox. If you indeed get an email from Microsoft, you should immediately
contact their customer service department to make sure it's a legitimate email.
Number 4 is Gameover Zeus. First discovered in 2011, Gameover Zeus or
GOZ is a peer-to-peer extension of the Zeus Trojan, also called Zbot, which is one of
the most successful botnet software in the world.
The malware uses spam emails and compromised websites to attack victims. Designed to steal
valuable information, GOZ collected personal information such as passwords, credit card
information as well as customer data and sensitive corporate information.
White Zbot was sophisticated enough to steal information from reputed organizations such
as NASA and Bank of America. GOZ itself infected thousands of corporations and nearly 1.2 million
computers before it was finally taken down. Being an advanced variant of the Zeus family,
GOZ is polymorphic malware with low detection rates, which makes it a highly persistent
threat. That's why it's one of the most successful and widespread botnets.
Its new version also contains a Necurs rootkit, making it hard to remove the malware unless
you wipe the infected client. But it can easily get infected again as the malware would still
exist somewhere in the P2P network. That's why a threat is always there. It can
only be controlled through intelligent software like Heimdal that blocks access to infected
addresses, websites, or computers and identifies the infection by studying communication attempts
between devices.
Let's move on to Number 3 with the PlugX virus. PlugX is a fully-featured Remote Access Trojan
or a RAT, early samples of which can be traced back to 2008. Researchers have recently found
a new variant of this malware called the "Korplug." The malware opens up backdoors and grants
full management of the machine it infects to the attackers. They can fully control the
device and execute commands from a remote location.
For instance, the attacker can retrieve machine information, capture the screen, reboot the
system, upload/download/modify files, manage processes, services, and Windows registry
entries, and perform keystroke logging. Like most other viruses, PlugX also spreads
through malicious emails that appear to be from legitimate service providers and even
carry signed executables or applications. That's why endpoint security products may
not flag them. If the emails carry a copy of legit antivirus-related
applications, the endpoint security may actually whitelist the product and let the malware
slip in the process. But the attachments usually carry three different files that make up the
PlugX components. PlugX typically targeted government institutions
and key industries. Another example of similar malware is Poison Ivy, which was aimed at
specific institutes, and it was used to target specific organizations in Japan back in February
2008. Due to its elusive nature, the malware is
hard to detect and block. The best way to deal with it is to have awareness and vigilance
against such attacks.
At Number 2, we have the Clop Ransomware. Like other ransomware, Clop Ransomware also
creates backdoors, encrypts all your files, blocks all access to system processes and
services, and demand a ransom. But what makes it more dangerous is that the
malware is evolving all the time, and its author is constantly employing innovative
techniques to make it more complex. First discovered by the MalwareHunterTeam
in February 2019, Clop is a variant of the CryptoMix Family. Clop is a Russian word meaning
"bug." The malware uses many different methods to victimize users, including spammed emails,
exploit kits, malvertisement, or compromised websites.
As soon as Clop infects a system, it immediately shuts down Windows services and processes
to disable the antivirus software. Then it closes all the files to start encrypting them.
The malware targets Microsoft Windows-based PCs, especially English-speaking users. However,
Clop is aimed at entire networks rather than individuals. The new variant is distributed
using executables that are code-signed with a digital signature, which makes it appear
legitimate and may help avoid detection by the security software.
For our most dangerous virus, we have CryptoLocker at number 1.
CryptoLocker or the Crypto virus was first spotted on 5th September 2013. This virus
continued spreading until June 2014 when Evgeniy Bogachev, the CryptoLocker gang leader, was
finally taken down. Although it's similar to other ransomware,
what makes it our top-most dangerous virus is that once it infects files, they are effectively
as good as lost forever. The malware also affects connected media, such as USBs and
shared network drives. CryptoLocker also uses the same methods to
get around as other ransomware types. In this case, though, the attached file appears to
be a legit Word or pdf file but actually hides an additional malicious extension.
The hackers encrypt files using asymmetric encryption. They encrypt your files using
a public key, but then you need a unique private key to unlock the information, which only
the hacker can give you. But there's a big question mark on whether or not you're going
to get that key even after paying the ransom money.
That's why the best way to protect yourself against such attacks is to be aware of what
emails to suspect. As a general rule of thumb, don't open any attachments that come to you
out of the blue. Always confirm the source before you download any attached files.
To sum up, the most important thing you need to care about is the security of your files
and the sensitive personal information stored on your computer.
As you have seen, many ransomware types even manage to bypass endpoint security, so you
must only rely on multi-level protection and make sure to always back up important data.
You also understand now that email is one of the most common methods attackers approach
you. So be vigilant and never open an attachment from an unknown source or even a known source
with unexpected or irregular correspondence. I hope you enjoyed this video and that it
helped you learn a lot about how attackers victimize you and how you can prevent malware
threats. If you have any questions, leave us a comment
below. We'd love to help you. While you're at it, don't forget to like,
subscribe and share. Don't forget to watch our next video. It’s
about the best antivirus software.