The U.S. Securities and Exchange Commission said on Tuesday it had charged three individuals for illegally tipping and trading in the securities of Equifax Inc before the company announced it had experienced a massive data breach.

Equifax, a provider of consumer credit scores, in September 2017 revealed that personal details of as many as 143 million U.S. consumers were accessed by hackers between mid-May and July that year, making it one of the largest data breaches in the United States.