A former Equifax executive has been accused of insider trading by federal regulators for allegedly dumping thousands of shares of the company's stock after a massive data breach at the credit reporting firm last year.

In a lawsuit filed Wednesday, the Securities and Exchange Commission said Jun Ying -- who at the time was chief information officer of a U.S. unit of Equifax -- sold about 6,800 Equifax shares after he learned of the breach but before the company had announced it publicly, amounting to an illegal trade based on insider information.

Ying sold those shares Aug. 28 for about $950,000. The SEC estimated that had he sold those shares after the breach was made public in September, he would have made $117,000 less. It also alleged that Ying sold shares shortly after researching how a smaller data breach in 2015 affected the stock price of Experian, an Equifax competitor.

Equifax shares plunged in value after the Atlanta-based credit-reporting company disclosed the breach Sept. 7. The company ultimately revealed that the personal information of nearly 150 million Americans was exposed. It is the largest-ever known breach of personal information data.

In September, the U.S. Justice Department opened a criminal investigation into whether top officials at Equifax had violated insider trading laws in connection with the breach.

Three Equifax Inc. senior executives -- Chief Financial Officer John Gamble, and Presidents Joseph Loughran and Rodolfo Ploder -- sold shares worth almost $1.8 million in the days after the company discovered the breach. Equifax has said those three executives had not been informed of the incident when they initiated the sales.