When a company experiences a data breach, the financial impacts of the compromise can be detrimental. Share prices are estimated to fall 3.5% within four months, and 8.6% after a year. But which global companies have experienced the most expensive data breaches? Recently, the team at Proxyrack conducted a study to look into the most costly data breaches, the most common methods, and the companies with the most data breaches to reveal the most exposed industries.

Top 10 most expensive data breaches

1. Epsilon (2011) — $4 billion
2. Equifax (2017) — $700 million
3. U.S. Office of Personal Management (2015) — $500 million
4. Veteran's Affairs (2006) — up to $500 million
5. Yahoo (2013-2014) — $470 million
6. Target (2013) — $300 million
7. TJ Maxx (2007) — $256 million
8. Marriott (2018) — $200 million
9. Sony Playstation (2011) — $171 million
10. Uber (2016) — $148 million

Other key findings include the following.

  • The Epsilon breach in 2011 saw the names and addresses of 60 million people stolen after the email system was breached. 
  • Equifax's $700 million breach in 2017 resulted in the private information of 160 million accounts being exposed — this further resulted in Wall Street lowering the company’s valuation by $4 billion.
  • The third most costly data breach was that of the U.S. Office of Personnel Management, which compromised personal data of more than 4 million employees. Ironically, the hack occurred whilst the company was updating their security.
  • 2011 saw the most data breaches, with 34 being recorded, this was closely followed by 2020 which experienced 31 and 2019 where 30 data breaches occurred.
  • The industry experiencing the most data breaches is the web, with 53 hacks recorded since 2004. This is followed by the healthcare industry, which has experienced 47.
  • Facebook is the company to have experienced the highest number of hacks, with a total of 5, followed by AOL and Citigroup who have both experienced 3 data breaches. 
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