The secretary of U.S. Homeland Security, Jeh Johnson, says "malicious" hackers who recently breached electronic safeguards to "scan" voting systems in a number of U.S. states do not appear to have manipulated any data.
Johnson was responding to suggestions following reported intrusions to election systems in Arizona and Illinois and the Democratic National Committee (DNC) that foreign cybercriminals were seeking to affect November's U.S. elections.
Officials have pointed a finger at Russia, where intelligence sources say at least some of the intruders were operating.
"In recent months, malicious cyberactors have been scanning a large number of state systems, which could be a preamble to attempted intrusions," Johnson said in a statement. "In a few cases, we have determined that malicious actors gained access to state voting-related systems. However, we are not aware at this time of any manipulation of data."
FBI Director James Comey told Congress recently that the his agency was looking "very, very hard" at Russian actors who could try to influence or disrupt the U.S. vote.
Russian President Vladimir Putin said of the DNC breach that "I don’t know anything about it, and on a state level Russia has never done this."