The most damaging cyber attacks

In this article, we will see some of the cyber attacks with the most dangerous computer viruses that caused a lot of damage not only virtual but also in real life, causing billions of dollars.

8. Mydoon

Appeared in 2004, Mydoom was a Windows worm that became one of the most widespread email worms. The author is unknown and is believed to have been paid to create it because it contains the message “I’m just doing my job, nothing personal, sorry.”.

The worm spreads by mimicking an error sending an email that contains an attachment. Once executed, it will send you all the email addresses you have in your contact list and also make a folder like a torrent to spread further.

Once entered into a new computer, it opens a backdoor to allow remote access and then launches an attack on the SCO group. It was believed that the worm was created to squander SCO’s work because of a conflict over the ownership of a Linux code. It caused $ 38.5 billion in damages and the virus is still active in some forms today.

7. Flashback

Although it was not as bad as the rest of the viruses, it is one of the few malware for the Mac that has gained notoriety and has proven that the Macs are not immune to malware. The Trojan was first discovered in 2011 by the Intego antivirus company as a fake flash installation.

In a newer version, a user simply needs to have Java enabled.
Trojan self-propelled by using compromised sites that contain Java Script code, which will download the content.

Once installed, the Mac becomes part of a BOT-net made up of other infected Macs.
The good news is that this malware only infects a specific user’s account. The bad news is that more than 600,000 Macs have been infected, including 274 Macs in the Cupertino area, Apple’s headquarters.

6. CryptoLocker

CryptoLocker is a form of ransomware or in other words a Trojan that asks for a ransom to release your encrypted files.

It runs on Windows and uses several methods to spread, such as e-mail. Once a computer is infected, it starts encrypting all the files on the hard drive and any other connected storage media.

Although it’s easy enough to remove this malware from the system, the files will still be encrypted. The only way to unlock the files is to pay a ransom up to a certain deadline. If the term is not met, the redemption will increase significantly or the decryption keys are deleted. The redemption usually amounts to $ 400 that will be paid through Bitcoin.

The data collected shows that the number of infected people amounts to 500,000 users, and the percentage of those who paid for data recovery is 1.3%, amounting to over 3 million dollars.

5. Zeus

Zeus is a Trojan horse made to infect Windows computers so they can perform various illegal tasks. The most common of these tasks are usually keylogging and a form of phishing.

Approximately 70 million dollars were stolen and more than 100 people were arrested because they were linked to the operation. At the end of 2010, the creator of the Zeus virus announced his withdrawal, but many experts consider this ad fake.

4. Sasser

A worm for Windows was discovered in 2004, a virus created by a computer science student named Sven Jaschan who also created the Netsky worm.

Although the effects of the virus were just annoying, making the computer slow and block, making it impossible to reboot just by disconnecting from the current, the effects resonated at a much higher level by making millions of infected computers of critical infrastructure affected.

The virus takes advantage of a vulnerability in the Local Security Authority Subsystem Service, which controls the security policy of local accounts, causing frequent crashes.

In all, the damages were estimated at 18 billion dollars, and Jaschan was tried as a minor and received a 21-month suspension sentence.

3. Code Red

Code Red first appeared in 2001 and was discovered by two eEye Digital Security employees. He was called Code Red because the two were drinking Mountain Dew Code Red at the time of the discovery.

The virus was targeting systems that used the Web server in Windows IIS exploiting a system buffer overflow problem. It leaves very few traces on the hard disk because it was able to run entirely in RAM with a size of 3679 bits.


The ILOVEYOU virus is considered one of the most violent computer viruses ever created.

The virus has managed to wreak havoc in systems around the world, causing damage to 10 billion dollars. 10% of computers connected to the Internet were infected with this virus. It was so aggressive that governments and big corporations disconnected network mail systems to prevent the infection.

The virus was created by two Filipino programmers, Reonel Ramones and Onel de Guzaman. They used social engineering to spread the virus, in this case, a declaration of love. The attachment file was actually a scribd that was presented as a text file because of the Windows that at the time hiding the real file extension. Once you clicked on the file, it was sent to all your friends and mailing lists. It overwrites over a lot of files in the system, making the computer stop running.

The two were never condemned because at that time there was no law against viruses.

1. WannaCry Ransomware

The most destructive computer virus infection in the last few years is a ransomware called WannaCry.

It was built on the phase of spyware stolen from the NSA (the SRI of the Americans), which the NSA used for espionage. Tools based on some Windows vulnerabilities, which the NSA did not report to Microsoft, were stolen and put on Dark Web, some of them with ideas put to work.

WannaCry comes with a message telling us to pay $ 300 if we want to decrypte the files. There’s even a 7-day time limit, after which you can not decrypt files anymore.
Three days later, the redemption amount is increased, from $ 300 to $ 600.

Protection measures against these viruses:

  • Update to operating system (important);
  • Backup your data to an external hard drive (very important);
  • Use an up-to-date antivirus;
  • Do not install pirated programs;
  • Do not visit suspicious sites;
  • Do not click on suspicious attachments in your email.

REMEMBER: The user is the best Antivirus! Be careful!

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