Secretary of State Connie Lawson says the federal Department of Homeland Security accessed the state’s electoral system without Indiana’s permission.
Thousands of altered registration records flagged might be due to residents rushing to correct their names or birth dates ahead of the election.
Voter turnout was expected to be low this year because there were no big-ticket races on the ballot.
Connie Lawson defeats Marion County Clerk Beth White in the race for Indiana Secretary of state.
Since the 2014 election lacks a major campaign on the statewide ballot, the Secretary of State’s race is at the top of the ticket.
The Secretary of State is in the middle of an effort to clean up the state's voter rolls.
Some Indiana voters are receiving a postcard from the state to confirm their active voting status.
At its state convention, the GOP selected Connie Lawson to run for secretary of state, Suzanne Crouch for auditor and Kelly Mitchell for treasurer.
The state of Indiana plans to spend $2.1 million to clean up its voter rolls.
Latest voter registration numbers show 13,000 fewer people are registered for this year's primary than four years ago.