NEW YORK (AP) — Embattled Equifax CEO Richard Smith stepped down Tuesday, less than three weeks after the credit reporting agency disclosed a disastrous hack to its computer system that exposed the sensitive personal information of 143 million Americans.

His departure follows those of two other high-ranking executives who left in the wake of the hack, which exploited a software flaw that the company did not fix to expose Social Security numbers, birthdates and other personal data that provide the keys to identify theft.

Smith, who had been CEO since 2005, will also leave the chairman post. Equ...