Famous Data Breaches & Phishing Attacks: What We Can Learn

Data breaches and phishing attacks are increasing in both frequency and intensity. In 2023, a record 3,205 data compromises were reported, which is an increase of 78% from the previous year. 

To tackle present and future attacks as effectively as possible, it is important to take a look at past real-world cyberattacks. It will help us identify patterns and common loopholes while also learning about best mitigation and prevention strategies. 

Notable Data Breach Examples

Here are some examples of famous data breaches: 

1. Facebook Data Breach (2019)

The 2019 Facebook breach exposed the personal information of 533 million Facebook users. The data was scraped from Facebook profiles by malicious actors who used the platform’s contact importer feature before September 2019.

The data breach affected users from 106 countries. It included 32 million records from the US, 11 million from the UK, and 6 million from India. This attack showed the importance of proper security configurations for cloud storage.

2. Sony PlayStation Network Breach (2011) 

In the Sony PlayStation Network Breach of 2011, personal details from approximately 77 million accounts were compromised. Users were prevented from accessing PlayStation 3, and PlayStation Portable consoles were prevented from accessing the service.

Legal action was taken against Sony. Additionally, the company had to compensate its users for the damages suffered. It is important to notify users of a possible security breach on time and protect members’ credit card information from unauthorized use. 

3. Colonial Pipeline Ransomware Attack (2021) 

This is one of the most famous data breaches that caused tremendous harm. On May 7, 2021, Colonial Pipeline, the largest fuel pipeline operator in the United States, fell victim to a ransomware attack. This forced the company to shut down its entire network. The attack compromised Colonial’s IT systems and led to the theft of 100 gigabytes of data. The pipeline transports 2.5 million barrels of fuel per day and supplies nearly half of the East Coast’s fuel, but as a result of the attack, it remained offline for several days. 

The shutdown affected 45% of the East Coast’s fuel supply and also threatened to impact U.S. consumers and the economy. The pipeline was shut down from May 7-12, 2021, and normal operations resumed only on May 15. Colonial Pipeline had to pay a ransom of 75 Bitcoin (approximately $4.4 million) to the attackers. The incident showed the importance of Multi-factor authentication (MFA) in preventing password-based attacks. 

4. Equifax Data Breach (2017) 

In 2017, Equifax, a major credit reporting bureau, suffered a massive data breach that exposed the personal information of 147 million Americans. 

Equifax was ordered to pay $700 million in individual compensation and civil penalties. The company had to pay an additional $275 million in civil penalties and compensation to 48 states, Washington, Puerto Rico, and the Consumer Financial Protection Bureau. What’s more, affected individuals were offered 10 years of free credit monitoring or a $125 payout. 

This event showed that it’s very important to implement security mechanisms on time to prevent similar cyberattacks.

5. Marriott International Data Breach (2018) 

In 2018, Marriott International discovered a massive data breach that affected its Starwood guest reservation database. The breach, which began in 2014, exposed the personal information of up to 500 million guests.

This data breach led to the exposure of sensitive data for up to 500 million guests, including 327 million with compromised passport numbers. Marriott faced a class-action lawsuit and a 5.6% drop in share price. The estimated loss was $1 billion in revenue for Marriott. 

A key takeaway from this was that it is necessary to implement encryption, network segmentation, and regular security audits, and it helped to see hotels as high-value targets for cybercriminals and nation-state actors. 

Notable Phishing Attack Examples

Some famous phishing attack examples are presented below.

1. Google and Facebook CEO Fraud (2013-2015)

In this attack, 48-year-old Evaldas Rimasauskas impersonated an employee of the Asian manufacturer Quanta Computer and defrauded Facebook and Google over several years. As a result, from 2013 to 2015, employees and agents of the two companies were tricked into wiring money (approximately $100 million) to his bank accounts.

The impact was huge! Google and Facebook lost a combined $100 million because of the attacks while also suffering reputational damage. 

There were a few key takeaways from this incident. Among other phishing case studies, this one showed the importance of implementing strict verification procedures for large transactions. It also underscored the importance of deploying DKIM, SPF, and DMARC to prevent domain spoofing and enhance email security.

2. The Democratic National Committee (DNC) Hack (2016)

The 2016 Democratic National Committee email leak encompassed numerous Democratic National Committee emails stolen by one or more hackers operating under the pseudonym “Guccifer 2.0.” It led to the leak of 19,252 emails and 8,034 attachments. 

The leak showed bias against Bernie Sanders’s campaign and led to many high-profile resignations, such as DNC chair Debbie Wasserman Schultz. The leaks also caused significant harm to Hillary Clinton’s campaign. 

This event showed that cyber attacks can have a massive impact on politics and even influence the outcome of presidential elections. 

3. Ubiquiti Networks Phishing Attack (2021)

In December 2020, Ubiquiti experienced a breach by an employee who was a senior cloud engineer at the company. This employee managed to mask his identity through a VPN, cloned the company’s GitHub repository, and changed logs in AWS to hide his presence and evidence of the breach. Once he leaked false details of the attack to a famous security blogger, Ubiquiti’s stock lost 4 billion USD in value.

As a result of this phishing scam, Ubiquiti’s stock price fell approximately 20% between March 30-31, 2021. This event showed the need for better monitoring and control of administrative access for cloud services. Another important lesson learned is that it’s important to conduct comprehensive background checks before hiring someone, especially for a senior position. Once hired, continuous monitoring is also necessary. 

4. Twitter Bitcoin Scam (2020) 

On July 15, 2020, 130 high-profile Twitter accounts (e.g., those of  Elon Musk, Bill Gates, Barack Obama, etc.) were reportedly compromised by outside parties to promote a Bitcoin “giveaway” scam. The attack promised to double any Bitcoin sent to specific wallet addresses. 

Nearly $118,000 worth of Bitcoin was stolen from around 400 victims of the scam. After the hack, Twitter’s stock price fell by 4%. A key lesson was that strong internal security protocols can prevent insider threats. It also showed that limiting and carefully monitoring employee access to internal tools and systems is crucial for preventing unauthorized use. Additionally, the incident underscored the need for public education about cryptocurrency scams and the irreversible nature of Bitcoin transactions.

5. Crypto Exchange Phishing Attacks 

Throughout 2023 and early 2024, there was a big increase in the number of crypto exchange phishing attacks. They often include fake login pages for popular exchanges and wallet services and malicious browser extensions to mimic legitimate crypto wallets.

The financial impact of crypto phishing attacks in 2023 was very big. Nearly $300 million in cryptocurrency assets were stolen from over 324,000 victims through wallet-drainer malware.

Hence, it is important to always double-check the website address before entering login credentials or connecting a wallet.

Recent Data Breaches and Phishing Cases

Recent famous data breaches and phishing cases include: 

Hospital Sisters Health System (2023)

Hospital Sisters Health System (HSHS) notified 882,000 patients about a data breach that resulted from a cyberattack in August 2023. The breach exposed names, birthdates, addresses, Social Security numbers, driver’s license numbers, medical record numbers, health insurance details, etc. 

MGM Resorts International (2023)

MGM Resorts experienced a significant cyberattack in September 2023 that disrupted its operations and services. The attack, attributed to a group known as “Scattered Spider,” involved sophisticated tactics including voice phishing and the deployment of a secondary Identity Provider (IDP). 

Grubhub Data Breach (2025)

Among recent famous data breaches, Grubhub is a major one that affected people from different walks of life. In February 2025, it was announced that a Grubhub data breach impacted an unknown number of Grubhub customers, campus diners, drivers, and merchants. The attack originated from a compromised third-party service provider account and exposed details as important as partial payment card information. Compensation may be available for those who were notified that their personal details were compromised.

Finastra (2025)

Finastra, a British financial technology firm, reported a data breach that occurred between October 31 and November 8, 2024. An unauthorized third party accessed their Secure File Transfer Platform (SFTP), which compromised sensitive customer information. 

Casio UK (2025)

Casio UK’s e-shop was hacked to encompass malicious scripts that stole credit card and customer details between January 14 and 24, 2025. Any customers who made purchases in this period may have had their credit card data and other information stolen by hackers. This attack was part of a larger campaign that affected at least 17 e-commerce sites.

Key Lessons from These Cyberattacks

Following Modern Email Security Practices

With changing times, it’s important to upgrade your security stack and incorporate modern solutions for modern problems! Instead of traditional email security practices, more sophisticated and evolving solutions like DMARC can be a game-changer! 

DMARC is an email authentication protocol that can help you control how you want unauthorized emails originating from your own domain to be treated. With DMARC, you can choose to block them out – thereby preventing the next big data breach or phishing scam. 

That’s not all! There is also BIMI – a modern take on email marketing with the combined security of authentication. BIMI helps you append brand logos to outgoing emails, ascertaining your brand identity and ensuring protection against impersonation. 

Some organizations also use scenario planning software to walk through possible data breaches or phishing situations in advance. This helps teams think through response steps, spot weaknesses, and feel better prepared if a real incident occurs.

Updating Software

It is crucial to consistently update your anti-spyware and anti-virus software since cybercriminals are continuously searching for weak, vulnerable computer networks with outdated security protection. Conducting regular checks can help you avoid outdated software and all the possible negative side effects it may have on your business. 

Data Encryption

Data encryption helps prevent any unauthorized access to or extraction of valuable information.

Encryption helps turn plain text into a complex, sophisticated, and incomprehensible format that cybercriminals cannot decode unless they have the encryption key. 

Regular Data Backups

Data backup systems are very important for protecting business information against various threats, including human errors, power failures, and malware attacks. These systems create copies of important data to ensure its availability in case of a security breach or data loss incident. 

Training Staff

One of the common causes behind the success of past and present phishing attacks and data breaches is that the staff members weren’t educated or trained well enough to protect themselves and the company’s data. Training the staff from time to time can help them stay informed about the newest threats and developments and thereby stay protected against future cybersecurity dangers. 

Firewalls

A firewall is an important component of network security that acts as a gatekeeper, helping monitor and control incoming and outgoing network traffic. It serves as the first line of defense against cyber threats, which in turn allows legitimate traffic to pass through while blocking potentially malicious or unauthorized access attempts. 

How PowerDMARC Helps Protect Against Phishing & Data Breaches

There are many ways PowerDMARC can help protect your business against phishing attacks and data breaches. These include: 

1. Full-Stack Email Authentication: PowerDMARC offers a complete range of hosted email authentication solutions, including DMARC, SPF, DKIM, MTA-STS, TLS-RPT, and BIMI. 
2. DMARC Enforcement: PowerDMARC enables organizations to implement and manage DMARC policies effectively, which helps block spoofed emails before they reach the recipients’ inboxes.
3. Threat Intelligence & Monitoring: Real-time monitoring and analysis of email traffic provided by PowerDMARC helps detect and prevent phishing attempts and other email-based threats.
4. AI-Driven Insights: PowerDMARC’s platform uses artificial intelligence to provide actionable insights and recommendations for improving email security posture.
5. Simplified Compliance: The platform simplifies DMARC compliance, which helps organizations achieve full protection within the least possible time!
6. Global Reach: PowerDMARC has reliable and 24/7 support, with translated dashboards and content in 11+ languages, making it a global solution to modern cybersecurity challenges.

Final Thoughts

As data breaches and phishing attacks are getting more sophisticated with time and the development of AI, they are more likely to cost businesses significant financial and reputational damage. There are still many security gaps across organizations worldwide; some of them lack advanced email filters, some others do not regularly conduct employee training, and many do not pay sufficient attention to email authentication protocols. The costs of such security gaps were explored through past and current examples of the biggest security breaches, which often resulted in court trials and significant losses of profits. Implementing DMARC, which can help authenticate whether an incoming email is from a legitimate sender or an unauthorized one, is an effective way to fight against ever-evolving cyber threats. However, keep in mind that implementing DMARC alone is not enough since the complex nature of cybersecurity requires a more comprehensive approach. This may include raising awareness, data encryption, software updates, and other email authentication protocols in addition to DMARC, like MTA-STS and BIMI, among others.

• About
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Milena Baghdasaryan

Content Specialist at PowerDMARC

Milena is a skilled writer and content creator with 7+ years of experience in crafting engaging content on IT, cybersecurity, virtual events, and more. She has a proven track record of delivering high-quality work for international magazines and is a graduate of prestigious institutions such as New York University Abu Dhabi, UWC China, and the College of Europe.

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