The computer network used by Democratic presidential candidate Hillary Clinton’s campaign was hacked as part of a broad cyber attack on Democratic political organizations, people familiar with the matter told Reuters. The latest attack, which was disclosed to Reuters on Friday, follows reports of two other hacks on the Democratic National Committee and the party’s fundraising committee for candidates for the U.S. House of Representatives. The U.S. Department of Justice national security division is investigating whether cyber hacking attacks on Democratic political organizations threatened U.S. security, sources familiar with the matter said on Friday.