In 2009, Heartland Payment Systems announced that it had suffered a devastating breach: 134 million credit cards were exposed through SQL Injection attacks used to install spyware on Heartland’s data systems. The company processes payments for debit, prepaid and credit cards, in addition to online payments and checks and payroll services. 

At the time of the breach, Heartland processed 100 million payment card transactions per month for 175,000 merchants, ranging from small to midsized retailers.