Equifax, the consumer credit monitoring company announced Thursday that hackers stole the personal information and other credit information from approximately 143 million Americans, putting them at risk of identity fraud.

“This is clearly a disappointing event for our company, and one that strikes at the heart of who we are and what we do,” Equifax CEO Richard Smith said in a statement. “I apologize to consumers and our business customers for the concern and frustration this causes.”

The hacks were discovered on July 29, but not made public for more than a month. The company’s stock fell 13 percent in extended trading after the announcement. According to Bloomberg News, three Equifax executives including CFO John Gamble sold a combined $1.8 million worth of Equifax stock in the days after the hack was discovered, but before it was made public.

Equifax will not be contacting everyone whose information was compromised. The company advised consumers to sign up for its TrustedID Premier program, which it will provide at no charge for a year.