The 5 Worst Computer Viruses of All Time
In the 1980s, the birth of the home computer gave rise to a new breed of criminal: the computer hacker. These skilled programmers used their knowledge to exploit weaknesses in computer systems and spread malicious code – or viruses – that caused devastation on a global scale.
While the motives of hackers have changed over the years – from pure mischief to political activism and even financial gain – their ability to wreak havoc remains as strong as ever.
In this article, we take a look at five of the worst computer viruses of all time, based on the damage they caused, the number of victims they impacted and the cost of the clean-up operation.
1. ILOVEYOU
Discovered: 5 May 2000
Also known as: VBS/Loveletter, Love Bug, Loveletter.VBS, Loveletter.vbs
Type: Worm
Discovered in May 2000, the ILOVEYOU virus was a classic example of social engineering at its finest.
Disguised as a love letter, the virus was actually a malicious piece of code that would overwrites vital system files, rendering a PC inoperable. It would then spread itself to all addresses in the victim’s Microsoft Outlook contact list.
Within 10 days of its release, ILOVEYOU had caused damage estimated at $5.5 billion and infected more than 50 million computers in over 100 countries.
2. Sobig.F
Discovered: 18 August 2003
Also known as: W32.Sobig.F@mm, W32/Sobig-F
Type: Worm
Sobig.F was first spotted in August 2003 and quickly became one of the fastest-spreading viruses of all time.
Unlike ILOVEYOU, Sobig.F did not rely on social engineering to spread itself – instead, it used a technique known as mass-mailing to send itself out to thousands of addresses at once.
At the height of its infestation, Sobig.F was responsible for around one-fifth of all virus-related emails being sent around the world. It is estimated to have caused damage in excess of $37 billion.
3. Mydoom
Discovered: 26 January 2004
Also known as: Novarg, ShimgAPI, Beagle, Doomjuice, W32.Mydoom@mm, W32/Mydoom@MM
Type: Worm
With a peak infection rate of around one in every twelve emails being sent, Mydoom was the fastest-spreading virus of all time when it was released in January 2004.
Like Sobig.F, Mydoom used mass-mailing to spread itself, but it also had a novel trick up its sleeve: it would use the victim’s own email program to send out the infected message, making it appear as if it came from a trusted source.
Mydoom caused an estimated $38 billion in damage and is believed to be responsible for taking down the website of the SCO Group, a US software company.
4.Conficker
Discovered: 21 November 2008
Also known as: Downadup, Kido
Type: Worm
Conficker is a complex and sophisticated piece of malware that is still active today, nearly 10 years after it was first released.
The virus is capable of stealing sensitive information, such as passwords and financial data, and can be used to launch attacks on other computers.
It is estimated that Conficker has infected over 10 million computers worldwide, with a large number of those being located in corporate networks. The virus has caused an estimated $9.1 billion in damage.
5. WannaCry
Discovered: 12 May 2017
Also known as: WCRY, WannaCrypt, Wanna Decryptor
Type: Worm
In May 2017, the world was brought to a standstill by the WannaCry virus, which used a previously undiscovered security flaw – known as a zero-day exploit – to spread itself rapidly across the globe.
The virus encrypted the files on infected computers and demanded a ransom be paid in order to decrypt them.
WannaCry caused major disruption to businesses, healthcare and critical infrastructure around the world, with the UK’s National Health Service being one of the worst affected. It is estimated to have caused damage in excess of $4 billion..Find Out More
The most destructive computer viruses
One of the most destructive computer viruses in history is known as the Love Bug virus. This virus, which was first released in May of 2000, quickly spread around the world, causing billions of dollars in damage. The Love Bug virus infected computers by email, causing the affected computers to send out copies of the virus to everyone in their address book. This resulted in a massive amount of email being sent out, clogging up email servers and causing many businesses to shut down. The Love Bug virus was eventually traced back to a student in the Philippines, who was later arrested.
While the Love Bug virus was certainly one of the most destructive computer viruses in history, it is not the only one. In the past few years, there have been a number of other viruses that have caused billions of dollars in damage. The most notable of these is the WannaCry virus, which was released in May of 2017. This virus spread quickly around the world, encrypting the files on infected computers and demanding a ransom in order to decrypt them. The WannaCry virus affected businesses in over 150 countries, and caused an estimated $4 billion in damage.
Another destructive computer virus is the NotPetya virus, which was released in June of 2017. This virus also spread quickly around the world, and like the WannaCry virus, it encrypted the files on infected computers. However, unlike the WannaCry virus, the NotPetya virus did not demand a ransom – it simply destroyed the files. This virus is estimated to have caused over $10 billion in damage, making it one of the most destructive computer viruses in history.
Visit malwarezero.org to learn more about what was the most dangerous computer virus. Disclaimer: We used this website as a reference for this blog post.