That amount of targeting and actual infiltration into state election-related systems is significantly larger than the U.S. government has been willing to acknowledge.
Hackers working on behalf of the Russian government are suspected in the onslaught against more than 20 state election systems, according to sources with knowledge of the matter.
He acknowledged there have been “some attempted intrusions at voter registration databases” since August, when the FBI issued a bulletin to state governments warning that hackers had infiltrated the Illinois State Board of Elections and tried to breach election systems in Arizona.
Testifying before the House Judiciary Committee, Comey said the FBI is trying to figure out "just what mischief is Russia up to in connection with our election."
He emphasized that voter registration databases -— not the voting system itself — are being targeted by hackers.
During a separate House hearing on Tuesday, Homeland Security Secretary Jeh Johnson said 18 states had reached out to his department seeking assistance in protecting their election systems.
Meanwhile, another top Homeland Security official and the head of the U.S. Election Assistance Commission both said a cyberattack could not change the outcome of the 2016 election.
Dr. Andy Ozment, the assistant secretary for cybersecurity and communications at DHS, told lawmakers on Wednesday that the hackers who broke into the voter registration system in Illinois and targeted a similar system in Arizona appear to have been looking to copy the personal information in those databases and perhaps then sell that information online. The aim was apparently not to affect the election process, he said.
"We have not seen intrusions intended to in any way impact individuals' votes and actual voting," Ozment said.
Not only did the hack apparently allow cyberoperatives to steal opposition research on Republican nominee Donald Trump, but many suspect it also led to the theft of internal messages that appeared to show efforts by DNC officials to undermine Democratic presidential candidate Bernie Sanders during the primary season.
In late June an "unknown actor scanned a state's Board of Election website for vulnerabilities" and, after identifying a security gap, exploited the vulnerability to conduct a "data exfiltration," or unauthorized data transfer, the FBI said in a recent bulletin.
Then in August, hackers used the same vulnerability in an "attempted intrusion activities into another state's Board of Election system," the FBI said.
"They believe we’re trying to influence political developments in Russia, we’re trying to affect change, and so their natural response is to retaliate and do unto us as they think we've done to them," he said.