8. Monster.com

Date: August 2007

Impact: 1.3 Million user information stolen

A group of hackers who had set up their server in Ukraine had breached into the most popular job recruitment site in US, allegedly by using High Profile user ids. The hackers generated spam and published them to other users to collect financial information. The hackers even blackmailed the user by installing viruses on their PCs and threatening them to completely format the systems if not paid.

7. Card System Solutions

Date: June 17 2005

Impact: 40,000 Card details stolen

The hackers sneaked into the company’s server using a Trojan SQL query. The tool inserted a code into the browser every four days and stole the card details of thousands of users. This came as a waking call for the company as they had not implemented any encryption on the user details.