Top 10 Well-Known Cyber Attacks

1. WannaCry Ransomware Attack (2017)

The WannaCry ransomware attack, launched in May 2017, was attributed to the Lazarus Group, a North Korean state-sponsored hacking organisation. It infected over 230,000 computers in 150 countries by exploiting a vulnerability in Microsoft Windows' Server Message Block (SMB) protocol (a system for sharing files and printers over a network)—specifically the EternalBlue exploit (a hacking tool developed by the NSA) that was leaked by the Shadow Brokers (a hacking group). The UK’s National Health Service (NHS) was among the hardest hit, causing widespread disruption in healthcare services. The motivation behind this attack was both financial gain through ransom payments and demonstrating North Korea's cyber capabilities.

2. NotPetya Malware Attack (2017)

NotPetya, unleashed in June 2017, was linked to the Russian military hacking group Sandworm, part of the GRU (Russia's military intelligence agency). It exploited the same EternalBlue vulnerability (a Windows exploit targeting outdated systems) as WannaCry, along with stolen administrative credentials (login details with high-level access), to spread rapidly. Targeting Ukraine’s infrastructure, it spread globally, affecting companies like Maersk, Merck, and FedEx. The attack was politically motivated, aiming to destabilise Ukraine’s economy while causing collateral damage worldwide.

3. Yahoo Data Breach (2013-2014)

The Yahoo data breaches, occurring between 2013 and 2014, were linked to Russian state-sponsored hackers seeking intelligence data. The attackers exploited outdated security measures and weak encryption practices (methods used to protect data) to steal data from 3 billion accounts, including names, emails, and security questions. The breach significantly damaged Yahoo’s reputation and reduced its acquisition value by Verizon. This attack exposed the consequences of inadequate security for user data.

4. Equifax Data Breach (2017)

The Equifax breach was attributed to a Chinese state-sponsored cyber-espionage group. They exploited an unpatched Apache Struts vulnerability (a flaw in a popular web application framework used for building websites) known as CVE-2017-5638, which allowed remote code execution (running malicious commands on a target system). This exposed sensitive financial data of 147 million Americans. The stolen data could be used for identity theft or espionage. The attack highlighted how critical personal data could be targeted for geopolitical and economic leverage.

5. Sony Pictures Hack (2014)

The Sony Pictures hack was carried out by North Korea’s Lazarus Group (who also orchestrated the WannaCry ransomware attack) in retaliation for The Interview, a film mocking North Korean leadership. The attackers used spear-phishing emails (highly targeted fraudulent emails used to trick victims into revealing sensitive information) to deliver malware (malicious software), gaining access to Sony's internal network. They leaked sensitive data, including unreleased films and employee information, causing massive financial and reputational damage. This politically driven attack showcased how cyber warfare could suppress free speech and intimidate corporations.

6. Stuxnet Worm (2010)

Perhaps one of the most famous and well-known attacks of the 21st century, Stuxnet was a covert cyber operation jointly developed by the US NSA and Israel’s Unit 8200. Stuxnet was a game-changer in cyber warfare, it exploited multiple zero-day vulnerabilities (previously unknown security flaws) in Windows and specifically targeted Siemens Step7 software (used to control industrial machines). Its goal was to sabotage Iran’s nuclear enrichment program by causing physical damage to centrifuges at the Natanz facility. This marked the first cyber attack to cause physical destruction, setting a precedent for using cyber weapons to achieve military objectives.

7. Target Data Breach (2013)

Eastern European cybercriminals breached Target through a third-party HVAC vendor (a heating, ventilation, and air conditioning contractor) by exploiting stolen credentials obtained via phishing (deceptive emails that trick users into giving up sensitive information). They installed RAM-scraping malware (software that captures data processed by a computer's memory) on point-of-sale systems, stealing credit and debit card information of over 40 million customers. This attack mainly aimed at financial theft but also exposed the risks of poor third-party security practices, costing Target millions in damages and a loss of customer trust.

8. Colonial Pipeline Ransomware Attack (2021)

In May 2021, the Russia-based DarkSide ransomware group attacked Colonial Pipeline by exploiting a compromised VPN account (a virtual private network used for secure remote access) that lacked multi-factor authentication (MFA) (an additional security layer requiring more than just a password). They encrypted company data, disrupting fuel distribution across the US East Coast. The group’s primary motive was financial gain, successfully extorting $4.4 million in Bitcoin.

9. Capital One Data Breach (2019)

The Capital One breach was executed by Paige Thompson, a former AWS (Amazon Web Services) employee. She exploited a misconfigured web application firewall (WAF) (a security system designed to filter and monitor traffic to and from a web application, much stronger than a normal firewall that works on the network level—WAF operates at the application layer) to gain access to data stored on AWS. Over 100 million customer records were compromised. This insider threat highlighted how internal knowledge and misconfigurations on network could lead to devastating data breaches.

10. SolarWinds Supply Chain Attack (2020)

Another very well-known attack, the SolarWinds breach, was orchestrated by APT29 (Cozy Bear), a Russian state-sponsored hacking group. They inserted malware, known as SUNBURST, into SolarWinds' Orion software updates (software patches designed to improve performance or security), exploiting the trust in supply chain software. This allowed them to infiltrate thousands of organisations, including US federal agencies. The motive behind this attack was gathering sensitive government and corporate intelligence.