Cyberattacks have existed for the longest time, ever since the existence of the internet. As time goes by, cybercriminals have been becoming more and more efficient when it comes to hacking servers, extracting sensitive information and injecting malicious codes. In this article, we are going to learn about the top 10 biggest cyber attacks in world history and their impact. 

List of Top 10 Biggest Cyber Attacks in World History

RankAttack NameDescriptionImpact
1Marriott Hotel Data BreachHackers stole personal information of 500 million guests over several years.Exposed sensitive data, financial loss
2WannaCry RansomwareGlobal ransomware attack infected millions of computers, demanding ransom payments.Disrupted businesses, financial losses
3Ukraine Power Grid AttackHackers infiltrated the power grid, causing widespread power outages for thousands.Critical infrastructure compromised, economic disruption
42014 Yahoo AttackHackers compromised user accounts, stealing personal information of 500 million users.Large-scale data breach, privacy violations
5Adobe Cyber AttackHackers stole user data and source code from Adobe, a major software company.Data breach, financial losses, reputational damage
6The PlayStation Network AttackHackers breached Sony’s PlayStation Network, compromising user data and disrupting services.Financial losses, reputational damage, user inconvenience
7Estonia Cyber AttackDenial-of-service attack targeted government websites, causing disruption and economic losses.Disrupted critical services, political impact
8NASA Cyber Attack15-year-old hacker breached NASA systems, shutting down critical computers.Security lapse, reputational damage, financial loss
9MOVEitHackers exploited a vulnerability in MOVEit file transfer software, compromising data of millions.Large-scale data breach, financial losses for organizations and users
10The Melissa VirusEarly email virus infected computers through a malicious file disguised as a free password list.Widespread damage, financial losses, cybersecurity awareness raised

1. Marriott Hotel Data Breach:

marriot data breach

In the year 2018, the Marriott hotel group revealed that they had fallen victim to a massive breach of data. The personal information of around 500 million guests had been acquired by a group of cybercriminals. The attack had been underway for a few years before 2018 and only came to light later on. But it did not end there. After another couple of years, data from around 5 million guests was exposed again. Again in 2022, 20 GB of data had been acquired by another set of cybercriminals, which included information such as legal documents of the hotel and payment information of the customers. 

2. WannaCry Ransomware:

WannaCry Ransomware

This cyberattack is one of the most well-known ones in the world. In the year 2017, the WannaCry Ransomware attacked digital devices on a global scale. It was initiated by the WannaCry Ransomware crypto worm and attacked approximately 2 lakh computers with Microsoft Windows software. Users of 150 countries fell victim to this attack and a loss of millions, potentially billions of dollars was incurred. 

3. Ukraine Power Grid Attack:

Ukraine Power Grid Attack

The Ukraine power grid attack had a huge impact on the entire Ukrainian nation. In this attack, the power grid of Ukraine was hacked and almost 2,30,000 users ran out of power in their houses for up to 65 hours. The group of cyber attackers that carried out this attack is part of an organization called “Sandworm”. This is one of the most well-known attacks that managed to negatively affect a large community. Other power stations in the area were also affected due to this attack.

4. The 2014 Yahoo Attack:

2014 Yahoo Attack

The 2014 Yahoo attack is one of the most detrimental attacks on a web browser in the history of cyber attacks. A state-sponsored actor managed to hack the accounts of at least 500 million users in the year 2004, but the event only came to light in 2014. Cyber attacks managed to extract extremely particular details about the users from their date of birth to their account passwords.  

5. Adobe Cyber Attack:

The cyber attack on Adobe, one of the leading software developing companies took place in the year of 2013. The accounts of at least 38 million users were compromised along with some important code of Photoshop, which is the picture editing service offered by Adobe. The initial statement given by the company stated that only around 2 million users had fallen victim to the attack but that was not the case. As a result, the company had to pay over 1 million dollars as a fine for this breach. 

6. The PlayStation Network Attack:

We all know how established Sony is in the digital landscape. But even the huge company could not escape a serious cyber threat. Also known as the PSN Hack, an external intruder managed to enter the server of PlayStation. Information from around 70 million people had been extracted by this intruder. Not only that but users were unable to access their PlayStation consoles. This breach lasted for around 23 days and PlayStation had lost money worth 1781 million dollars due to various lawsuits. 

7. Estonia Cyber Attack:

In 2007, Estonia became the first country where a cyber attack took place on an entire company. Around 58 websites suddenly went offline, including some very important government websites. The reason why this attack happened was due to a political dispute related to the displacement of a particular community of people to the outskirts of the city. The Estonian government incurred a loss of around US$1 million, because of this attack.

8. NASA Cyber Attack:

This attack was one of the first cyber attacks to involve a major space agency. The breach that took place managed to shut down over 20 important computers within the NASA headquarters. The whole world was taken aback when it was revealed that the person behind this breach was a 15-year-old computer hacker. NASA had to pay thousands of dollars to repair the damage done by this breach. 

9. MOVEit:

This is one of the most recent and one of the most prominent cyber attacks in world history. It took place in the year 2023 when Progress Software introduced Zero-Day Vulnerability in its MOVEit file-transferring software. This vulnerability gradually became a liability as hackers and cyber attackers around the world could now easily access information of its users and inject malicious codes. By the end of September, almost 2000 organisations had been negatively impacted and data of nearly 60,000,000 people was compromised. This attack had a lasting impact, not only on the users but also on the financial resources of the company.

10. The Melissa Virus:

The Melissa virus attack is the oldest one in this list, but still had a huge impact globally. An AOL account was hacked by someone named David Lee Smith. he published a file promising free passwords to adult websites, and when people tried to access that,  it injected a virus into the device. A large number of computers were damaged due to this virus and it took a significant amount of time to remove it from their systems. Inquiring a loss of around US$80 million, this attack managed to teach a lesson to people about cyber security.

There are many types of cyber attacks now due to the growth of technology. The safety of your devices is in your hands, make sure to take all necessary precautions.