A Quick Guide to the Worst Corporate Hack Attacks
By Keith Collins
| Updated March 18, 2015
The recent attack on Premera Blue Cross is the latest in a long series of data breaches at corporations in the U.S. by hackers seeking customer credit card numbers, user passwords, internal documents and emails. Here’s a tally of what hackers have made off with, and how the stock market reacted—or didn't—in the immediate aftermath.
Premera Blue Cross

Announced: 03/18/2015

The company, which discovered the breach in January, says hackers may have accessed Social Security numbers, bank accounts and medical information.

Private company, N/A
Records lost 11M
Types of records Credit card numbers
Bank accounts
Social Security numbers
Proprietary information
Employee details
Email addresses
Physical addresses
Login credentials
Data Breaches Since 2005
Since 2005, more than 75 data breaches in which 1,000,000 or more records were compromised have been publicly disclosed. The attacks on Home Depot and EBay in 2014, and on Target at the end of 2013, indicate an increase in attacks on retail and merchant data.