A massive cyber security incident at Equifax — one of the largest credit reporting agencies in the United States — may have exposed private information belonging to 143 million people — nearly half of the U.S. population.

The breach, which was discovered July 29, includes sensitive information such as social security numbers, birthdays, addresses, and in some instances, driver’s license numbers. The agency said 209,000 credit card numbers were exposed in the breach, which includes customers in Canada and the United Kingdom.

Adding to the scandal, three of the company’s top executives sold Equifax shares just days after the breach was discovered. The breach was not publicly disclosed until Thursday, more than six weeks later.

John Gamble, chief financial officer; Joseph Loughran, president of U.S. information security; and Rodolfo Ploder, president of workforce solutions solutions, all sold shares days after the company was aware of the breach, according to SEC filings. Bloomberg, which first reported this, estimated the total value of shares sold to be $1.8 million.

An Equifax representative told NBC News the three executives sold a “small percentage” of their shares and “had no knowledge that an intrusion had occurred at the time they sold their shares.”

The FBI is actively investigating the cyber incident and Equifax has been cooperating, law enforcement sources told NBC News.

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