The Democratic National Committee said Thursday that a thwarted attempt to hack into its voter database was actually a test built by an unnamed third party.

On Wednesday, the DNC said it contacted law enforcement after detecting a suspected cyberattack on Tuesday. The Democratic Party added that it stopped the hacking attempt, and attackers did not modify voter data.

In a statement, DNC Chief Security Officer Bob Lord said the test "mimicked several attributes of actual attacks" on the party's voter database, VoteBuilder. However, he said neither the DNC nor VoteBuilder or any of the party's security vendors authorized the test.

"The party took the necessary precautions to ensure that sensitive data critical to candidates and state parties across the country was not compromised," Lord said. "There are constant attempts to hack the DNC and our Democratic infrastructure, and while we are extremely relieved that this wasn't an attempted intrusion by a foreign adversary, this incident is further proof that we need to continue to be vigilant in light of potential attacks."

The DNC's revelation Wednesday set off alarm bells ahead of November's midterm elections. The U.S. intelligence community has warned that foreign cyberattackers could strike again in an attempt to influence this year's election. Microsoft and at least one key politician have said that hacking attempts have already started.

Intelligence officials concluded that Russia carried out a campaign to influence the 2016 election, which included a cyberattack on the DNC.