Famous Virus Attacks

In the first part of this series, we looked at what viruses were and how they worked. Now, to put that into context, let’s run through some of the most infamous virus attacks in the last two decades. Before we proceed, bear in mind this sinister fact: once a virus is conceived, it never really ceases to exist — and the five viruses below remain alive and active in some form.


In May 2000, the ILOVEYOU virus shut down the email servers of several major corporations, including Microsoft and Ford. After just ten days, ILOVEYOU had affected around 45 million users and caused approximately $10 billion in damages.  The scale, speed and damage of ILOVEYOU has led many cybersecurity experts to regard it as the first true global, large-scale attack, and an introductory precursor to the new millennium — and the dangers we face.

2. Mydoom

It was back in early 2004 that MyDoom commenced sending spam junk mail via infected computers and hitting several large tech corporations, including Microsoft and Google. Mydoom utilized a distributed denial-of-service attack (DDS), which has only become more common in the years since. Some estimates claim it infected up to one quarter of all emails that year — a horrifying figure. Even conservative estimates have it at between 16%–25%.

3. Storm Worm Trojan Horse

Back in January 2007, much of Europe was gripped by panic over Storm Kyrill. This Trojan horse was initially spread through email communication on the topic of the storm, hence the christening with the name, “Storm Worm”.

It then evolved to use a multitude of clickbait titles as the hook, for example: “Saddam Hussein safe and sound!” and “British Muslims Genocide”. It also had an encore on the 1st April 2008, with sinister April Fool’s Day topics instead. Many speculate the virus originated from Russian hackers — a common theme in the years since.

4. CryptoLocker 

CryptoLocker was another Trojan that terrorized the web back in 2013/14. It was spread via phishing emails (and malicious attachments). Like many viruses, it worked by encrypting victims’ files — the hackers then demanded a ransom in order to unlock the files (normally 400 USD or Euro).

Eventually it was taken down by various bodies — such as the FBI and Interpol — in Operation Tovar. It has since been difficult to estimate the economic damage, as the figures for people who paid the ransom appear to be vastly different depending on sources; nonetheless, it ran to many millions of dollars.

5. WannaCry

12th May 2017. That is the date many experts claim WannaCry changed cybersecurity forever. It was the biggest attack the world had ever seen and resulted in great aftershocks in the worlds of business, politics, hacking and the cybersecurity industry.

WannaCry hit over 300 organizations spread across a huge 150 countries. It was so large that even after the kill-switch was found, the virus continued to terrorize all systems and data it had hitherto come into contact with.

Estimates put the total cost at over $4 billion, the UK’s NHS alone suffering over £92 million worth in damage. The attack was traced to the Lazarus Group, which has strong links to North Korea, but an air of mystery still clouds the details on what exactly happened.

Now that we’ve covered the five most infamous virus attacks, why not head over to the [third and final part]of this series for the prevention, symptoms and removal of viruses.