www.businessinsider.com/ap-sec-reveals-2016-hack-that-breached-its-filing-system-2017-9
www.bracewell.com/news/cyberattacked-sec-joins-club
www.natlawreview.com/article/who-s-watching-watchdog-sec-deals-its-own-data-breach
www.natlawreview.com/article/sec-wants-to-collect-more-information-can-they-protect-it
Update:
www.barnesville-enterprise.com/news/20170926/sec-chairman-faces-questions-from-congress-after-data-breach
www.findknowdo.com/news/06/05/2023/sec-regrets-database-deficiencies-adjudication-memoranda