Top 10 Most Destructive Computer Viruses of All Time

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Top 10 Most Destructive Computer Viruses of All Time
Network Security Jacksonville FL

Computer viruses and hacks cost U.S. businesses $109 Billion a year.

With such high stakes, it pays to be vigilant. But unless you know what you’re up against, it can be hard to take network security seriously.

Read on as we take a look at 10 of the worst computer viruses of all time.


The ILOVEYOU virus posed as a love confession. It would send itself to users’ mailing lists and overwrite files, making computers unbootable.

Thought to be one of the most harmful ever created, damages were upwards of $10 billion.

2. Code Red

Code Red targeted Microsoft IIS users and even the White House website was hit.

Once infected, the virus would replicate itself, taking up computer resources. The virus would then open up the machine to a remote access.

It hit a total of two out of six million IIS servers!

3. Melissa

This virus started in 1999 as an infected word document. This was posted online, claiming to be a list of passwords to adult websites.

Once opened, it would mail itself to the user’s email contacts. The increased email traffic caused disruption to governments and corporations alike.

4. Storm Trojan

In 2007, Storm Trojan infected thousands of computers. Users activated it by opening emails with titles such as “230 dead as storm batters Europe”.

Then, a program called wincom32 would install itself. This passed information to other infected computers. These computers would then spread the virus.

5. Sasser

Sasser affected millions of Windows XP and 2000 computers. It found a way to manipulate an exploit in the Local Security Authority Subsystem Services.

Sasser slowed machines down and caused crashes. It also made it hard to power down. Damages were estimated in the billions of dollars as well as forcing airlines and governments to shut down.

6. My Doom

One of the fastest spreading virus of all time, My Doom, infected one in 12 emails at its peak.

Users would open an attachment like “Mail Transaction Failed”. Its aim was to take down websites like Google and Lycos. It managed to take out Google for almost a day!

7. Zeus

In 2009, Zeus targeted windows computers to use them to perform criminal acts. It infected targets through phishing scams or downloads.

It compromised accounts from many leading banks and corporations. It stole details of social media accounts, bank accounts, and email addresses.

Around $70 million was stolen and over 100 arrests made.

8. Conficker

Conficker is a worm that infected over 9 million computers around the world.

It would reset account lockout settings and block access to antivirus sites and windows updates. It would then lock out user accounts. Scareware was then used to scam money from users.

9. Stuxnet

Believed to be created by Israeli and American defense forces for cyber warfare, Stuxnet was used to disrupt Iran’s nuclear program.

Spread through infected USB drives, it ruined 1/5 of Iran’s nuclear centrifuges. If the infected computer used Siemens software, it would alter the speed of the machinery it controlled, causing it to tear apart.

10. CryptoLocker

Cryptolocker was one of the first ransomware attacks. This virus encrypted files on hard drives. The only way to remove the encryption was to pay a ransom by a certain deadline.

Law enforcement managed to stop the ransom operation, but not before $27 million was paid.

Avoid the Worst Computer Viruses

As you can see, the worst computer viruses can cause serious problems. Unless you’re protected, you can lose your files, money or even equipment!

To keep your network secure, contact us. At Advanced Computer Consulting we can check your network and help you to protect your computer.

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