What are the top 10 most dangerous computer viruses?

In the world of computer viruses, there are classics like the ILOVEYOU virus which have been around for years, and newbies like the WannaCry ransomware which struck in May of 2017. Here is a list of the top 10 most dangerous computer viruses, in no particular order.

1. ILOVEYOU

Also known as Love Letter, this virus first hit the scene in 2000 and infects victims’ computers by disguising itself as a love letter. The email attachment seems innocuous enough, but when opened, the virus begins to replicate and send itself out to everyone in the victim’s contact list. ILOVEYOU quickly spread around the world, infecting millions of computers and causing an estimated $5.5 billion in damage.

2. Melissa

Named after a topless dancer in Florida, Melissa was one of the first mass-mailing computer viruses. It appeared in 1999 and, like ILOVEYOU, used email to spread itself. When victims opened the infected attachment, the virus would replicate and send itself out to the first 50 people in their Microsoft Outlook contact list. The virus caused so much disruption that some companies had to shut down their email servers to prevent infection.

3. Cryptolocker

This ransomware first popped up in 2013 and quickly rose to prominence as one of the most dangerous computer viruses around. Cryptolocker encrypts victims’ files and demands a ransom be paid in order to decrypt them. The ransom is typically between $200 and $400, payable in Bitcoin. While some victims have been able to get their files back by paying the ransom, there is no guarantee that they will be able to decrypt them.

4. WannaCry

WannaCry is a ransomware virus that hit the scene in May of 2017. It quickly spread around the world, infecting more than 230,000 computers in 150 countries. WannaCry encrypts victims’ files and demands a ransom be paid in order to decrypt them. The ransom is payable in Bitcoin, and it doubles after three days. WannaCry is particularly dangerous because it takes advantage of a vulnerability in Microsoft Windows that allows it to spread quickly and easily.

5. SoBig

SoBig first appeared in 2003 and quickly became one of the most prolific computer viruses ever. It infected more than 250,000 computers in just over a week and caused an estimated $37 million in damage. SoBig used email to spread itself, and it would often disguise itself as a message from a friend or a legitimate company. Once a victim opened the attachment, the virus would install itself and begin replicating.

6. MyDoom

MyDoom first appeared in 2004 and is considered to be one of the most destructive computer viruses ever. It caused an estimated $38 billion in damage and infected more than 1 million computers. MyDoom spread itself through email attachments and was designed to launch denial-of-service attacks against certain websites. It also included a back door that allowed hackers to remotely access the infected computer.

7. Sasser

Sasser first hit the scene in 2004 and quickly spread around the world, infecting more than 1 million computers. It took advantage of a vulnerability in the Windows operating system and did not require any user interaction to spread. Once a computer was infected, Sasser would start to launch denial-of-service attacks against certain websites. It also caused infected computers to crash and reboot repeatedly.

8. Conficker

Conficker first appeared in 2008 and is still active today. It has infected more than 10 million computers and is considered to be one of the most sophisticated computer viruses ever. Conficker spreads itself by exploiting vulnerabilities in the Windows operating system and by spreading through infected USB drives. Once a computer is infected, Conficker can be used to launch denial-of-service attacks, steal information, and log keystrokes.

9. Stuxnet

Stuxnet is a computer virus that was first discovered in 2010. It is believed to have been created by the United States and Israel to target Iran’s nuclear program. Stuxnet is a particularly insidious virus because it is designed to spread through industrial control systems, such as those used in nuclear facilities. Once it infects a system, it can cause the equipment to malfunction or even destroy it.

10. Zeus

Zeus is a Trojan horse virus that first appeared in 2007. It is designed to steal banking information by infecting computers and capturing login credentials as they are typed. Zeus can also be used to launch denial-of-service attacks. Zeus is particularly dangerous because it is difficult to detect and remove once it has infected a computer.

What are the most dangerous computer viruses and what do they do?

There are many dangerous computer viruses, with new ones appearing all the time. Here are some of the most dangerous viruses and what they do:

1. WannaCry: This ransomware virus encrypts all the files on an infected computer, making them inaccessible. The victim is then asked to pay a ransom in order to receive the decryption key. WannaCry has caused millions of dollars in damage since its release in 2017.

2. Zeus: This virus is used to steal banking information such as login credentials and account numbers. It can also be used to steal other sensitive information such as passwords. Zeus is particularly difficult to remove once it has infected a computer.

3. Conficker: This virus prevents computers from accessing certain websites, including security-related websites. This makes it difficult to protect infected computers from further attacks. Conficker can also spread itself to other computers on a network.

4. Stuxnet: This virus was designed to damage industrial equipment, such as the centrifuges used in nuclear facilities. Stuxnet is believed to have caused significant damage to Iran’s nuclear program.

5. ILOVEYOU: This virus spreads itself via email, displaying a message that appears to be from a loved one. Once opened, the virus installs itself on the victim’s computer and attempts to spread itself to other computers. ILOVEYOU specifically targets Microsoft Outlook and Outlook Express.

These are just some of the most dangerous computer viruses. New viruses are appearing all the time, so it’s important to have up-to-date anti-virus software installed on your computer and to be vigilant when opening emails and attachments.

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