The Top 5 Most Dangerous Cyber Attacks of all Time

Alex Archondakis

Managing Consultant

Alex is one of our managing consultants here at Pentest People. Focusing mainly on web application penetration testing. Alex has spoken at many key events while with us, including BSides London and even DSS ITSEC Latvia.

The Top 5 Most Dangerous Cyber Attacks of all Time

Cyber attacks are on the rise, and they show no signs of slowing down. In fact, many experts believe that we are only seeing the tip of the iceberg when it comes to cybercrime. As businesses continue to move their operations online, they become increasingly vulnerable to cyberattacks. In this blog post, we will take a look at the five most dangerous cyberattacks in history. These attacks have caused billions of dollars in damage and affected millions.

1. The WannaCry Ransomware Attack (2017)

The first attack on our list is the WannaCry ransomware attack. This attack hit businesses and organisations all over the world in May of 2017. The WannaCry ransomware encrypted data on victims’ computers and demanded a ransom payment in order to decrypt the data. This attack affected more than 200,000 computers in 150 countries.

The WannaCry ransomware attack was particularly dangerous because it exploit a vulnerability in Microsoft Windows that had been previously unknown. This meant that many organisations were not prepared for this type of attack. The WannaCry ransomware also spread quickly, thanks to a feature that allowed it to spread itself from one computer to another.

While the WannaCry ransomware attack was devastating, it could have been much worse. Fortunately, a security researcher discovered a kill switch that stopped the spread of the malware. However, this did not stop the damage that had already been done.

WannaCry

2. The NotPetya Virus (2017)

The next attack on our list is the NotPetya virus. This virus was first discovered in June of 2017 and quickly spread around the world, which caused a wave of cyber attacks to occur, causing billions of dollars in damage. The NotPetya virus encrypted victims’ hard drives and prevented them from accessing their files. Many businesses were forced to shut down as a result of this virus.

The NotPetya virus was particularly dangerous because it masqueraded as ransomware. This allowed it to spread quickly, as people were tricked into downloading and installing the malware. However, unlike typical ransomware, the NotPetya virus did not provide a way for victims to recover their data. This made it much more destructive.

The NotPetya virus affected businesses of all sizes, but it hit Ukrainian organizations particularly hard. This is because the virus was initially spread through a piece of accounting software that was popular in Ukraine. From there, it quickly spread to other countries.

While the NotPetya virus caused billions of dollars in damage, its true purpose is still unknown. Some experts believe that it was created as a form of information warfare, while others believe that it was simply a prank gone wrong. Either way, it is clear that the NotPetya virus was one of the most destructive cyberattacks in history.

NotPetya Malware

3. The Equifax Data Breach (2017)

The third attack on our list is the cyber attack rightfully named the Equifax data breach. Private records of 147.9 million Americans along with 15.2 million British citizens and about 19,000 Canadian citizens were compromised in the breach, making it one of the largest cybercrimes related to identity theft. The hackers gained access to sensitive information such as social security numbers, dates of birth, and addresses. This breach had a major impact on the credit reporting agency and its customers.

The Equifax data breach was particularly dangerous because of the sensitive information that was compromised. This information can be used to commit identity theft and other crimes. The breach also affected a large number of people, which made it one of the largest data breaches in history.

In the wake of the Equifax data breach, many people criticized the company for its poor security practices. The hackers were able to gain access to Equifax’s systems by exploiting a known vulnerability that had not been patched. This showed that Equifax had not taken proper steps to protect its customers’ data. Further proving the benefit of regular Penetration Testing, to highlight new vulnerabilities and remediate them before you’re the victim of such an attack.

The Equifax data breach is an important reminder of the importance of cybersecurity. Organisations must take steps to protect their customers’ data, or they will face serious consequences.

Equifax DataBreach

4. The Mirai Botnet Attack (2016)

The fourth attack on our list is the Mirai botnet attack. This attack took place in October of 2016 and targeted internet-connected devices such as routers and cameras. The Mirai botnet was used to launch denial-of-service attacks against websites and businesses. These attacks caused billions of dollars in damage and affected millions of people.

The Mirai botnet cyber attack was particularly dangerous because of the way it was carried out. The attackers used a network of infected devices to launch their attacks. This meant that the attacks could come from anywhere in the world. Additionally, the Mirai botnet was able to infect a large number of devices, which made it very powerful.

Despite its power, the Mirai botnet was eventually brought down. The attackers were arrested and sentenced to prison. However, the damage that they caused is still felt today. The Mirai botnet attack showed how vulnerable internet-connected devices can be and how destructive a cyberattack can be.

Mirai Cyber Attack

5. The Yahoo Data Breach (2014)

The fifth and final attack on our list is the Yahoo data breach. This massive data breach occurred in 2014 and affected more than three billion Yahoo users. The hackers gained access to sensitive information such as names, dates of birth, addresses, and passwords. This breach had a major impact on the internet giant and its customers.

The Yahoo cyber attack is the largest data breach in history. The sheer scale of the breach is staggering. Additionally, the sensitive information that was compromised could be used to commit identity theft and other crimes. The cyber-attack targeted 500 million accounts and obtained account names, email addresses, telephone numbers, date of births, hashed passwords, and some encrypted and unencrypted security questions.

The hackers were able to gain access to Yahoo’s system due to a single click on a spear phishing email, the FBI disclosed in 2016. Staff training regarding phishing is crucial in this day and age and needs to be taken seriously by businesses of all sizes.

Yahoo cyber attack

Conclusion

These attacks have caused billions of dollars in damage and affected millions. Cybersecurity is an important issue that organisations must take seriously. Otherwise, they will face serious consequences as shown by the above examples.

Regular Penetration Testing can help highlight new vulnerabilities and remediate them before you’re the victim of such an attack. Data breaches and sophisticated attacks are becoming more common, and they are only going to become more damaging as time goes on.

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