Hackers breached the U.S. Securities and Exchange Commission¡¯s computer system last year by taking advantage of companies that used authentic financial data when they were testing the agency¡¯s corporate filing system, according to sourcesr.

The Federal Bureau of Investigation and the U.S. Secret Service have since launched an investigation into a 2016 hack into the SEC¡¯S EDGAR system, several of those people said.

The sources spoke anonymously because it is not a public investigation.