CHICAGO (AP) — An attempt to break into the Democratic National Committee's massive voter database has been thwarted, a party official said Wednesday, two years after Russian operatives sent the party into disarray by hacking into its computers and facilitating the release of tens of thousands of emails amid the presidential election.

A web security firm using artificial intelligence uncovered the attempt. The DNC was notified Tuesday, it said. Hackers had created a fake login page to gather usernames and passwords in an effort to gain access to the Democratic Party's voter file, a party offic...