The U.S. Department of Homeland Security detected five “critical” cyber security weaknesses on the Securities and Exchange Commission’s computers as of January 23, 2017, according to a confidential weekly report reviewed by Reuters. The report’s findings raise fresh questions about a 2016 cyber breach into the SEC’s corporate filing system known as “EDGAR.” SEC Chairman Jay Clayton disclosed late Wednesday night that the agency learned in August 2017 that hackers may have exploited the 2016 incident for illegal insider-trading.