The 5 biggest data hacks of 2019
Hackers have accessed over 7.9 billion consumer records so far this year, with experts predicting that over 8.5 billion accounts will be exposed by the end of the year. The majority of the over 5,000 data hacks this year Risk Based Security has tracked so far consisted of only a few million accounts. Yet there were a few mega hacks that involved hundreds of millions. The Identity Theft Resource Center provided CNBC Make It with a ranking of the biggest data breaches announced in 2019, based on the number of accounts compromised. ITRC ranked only breaches that it could confirm the number of records affected. Several companies, such as 7-Eleven, WhatsApp and Fortnite, reported security flaws that could have exposed millions of customers' data, but the extent of the accessed data was not reported. Here's a look at the biggest data breaches of 2019, as well as tips on how to protect your accounts.

5. Quest Diagnostics

Number of records hacked: 11.9 million In early June, lab-testing company Quest Diagnostics announced that it found a data breach affecting its billing and collections vendor, the American Medical Collection Agency. The breach exposed the medical, financial and personal information of about 11.9 million customers over the course of eight months. That included credit card numbers, bank account information, medical information and Social Security numbers. The AMCA hack also affected LabCorp, which said personal and financial data on 7.7 million of its consumers was also exposed. Just weeks after the breaches were announced, AMCA filed for bankruptcy, citing "enormous expenses" the company racked up notifying customers of the breach and the fact that several of its biggest customers decamped. LabCorp and Quest Diagnostics both dropped AMCA after they learned of the breach, as well as Conduent and CareCentrix.

4. Houzz

Number of records hacked: 48.9 million Home design website Houzz kicked off the year by informing customers hackers had accessed usernames and encrypted passwords, as well as publicly visible profile information. The company's FAQ on the breach was vague, but ITRC reports 48,881,308 accounts were affected. No financial information was taken, Houzz said, adding that it became aware of the breach in December 2018.

3. Capital One

Number of records hacked: 100 million Capital One announced a massive data breach in late July, reporting that a hacker accessed the information of over 100 million Americans and 6 million Canadians who have applied for credit cards since 2005. The company says the applications the hacker accessed were from 2005 through early 2019 and contained consumers' personal information including names, addresses, zip codes, email addresses, phone numbers and dates of birth. Bank numbers and Social Security numbers were compromised for roughly 140,0000 U.S. credit card customers and about 80,000 secured credit card customers who had their linked bank account numbers accessed. Unlike other major hacks, the data accessed during the Capital One breach included sensitive data, such as Social Security numbers.

2. Dubsmash

Number of records hacked: 161.5 million In February, video messaging app Dubsmash announced that hackers nabbed nearly 162 million users' account holder names, email addresses and hashed passwords. Hashed passwords are encrypted, so they must be cracked before they can be used. The breach actually occurred in December 2018, but cyber thieves posted that the data was for sale on the dark web in February. It was part of a data dump that included over 600 million accounts from 16 hacked websites.

1. Zynga

Number of records hacked: 218 million Mobile game producer Zynga announced in October that a hacker had accessed account log-in information on Sept. 12 for customers who play the popular "Draw Something" and "Words with Friends" games. In addition to the log-in credentials, the hacker accessed usernames, email addresses, log-in IDs, some Facebook IDs, some phone numbers and Zynga account IDs of about 218 million customers who installed iOS and Android versions of the games before Sept. 2, 2019.

How to protect your data