Electronic voting machines have come under scrutiny for inaccuracy and lack of security.
Electronic voting machines have come under scrutiny for inaccuracy and lack of security. REUTERS

The first-known case of a cyberattack against online election data has occurred in South Florida, where more than 2,500 “phantom requests” for absentee ballots were reportedly recorded last summer.

Those requests were sent to the Miami-Dade County elections website using a computer program, according to a grand jury report published by NBC News on Monday. According to The Miami Herald, which first reported on the incident last month, the requests originated from only a handful of Internet Protocol addresses that “had all the appearances of a political dirty trick, a high-tech effort by an unknown hacker to sway three key Aug. 14 primary elections.”

The purported targets were Florida’s 26th congressional district, a new district created as a result of the 2010 Census, and Florida state’s 103rd and 112th districts.

“It’s the first documented attack I know of on an online U.S. election-related system that’s not [involving] a mock election,” David Jefferson, a computer scientist on the board of directors of the Verified Voting Foundation, told NBC News.

When those phantom requests were flagged, Florida election staff checked with voters to see if they had actually requested an absentee ballot. Although state officials blocked the Internet Protocol address the requests originated from, the hacker eventually switched to different addresses.

The grand jury report states the mysterious requests eventually stopped. The hackers were never identified.

Although there have been allegations of U.S. election system hacking in the past – such as a 2006 incident in Sarasota, Fla., when a computer worm allegedly dismantled the county elections voter database – investigations into those events have traced them to software glitches or machine failures.

The fear of potential cyberattacks isn’t only centered on elections data. Congressional lawmakers – and even President Barack Obama -- are becoming increasingly concerned about falling victim to a potentially “catastrophic” cyberattack, according to The Hill, which reports the topic has received renewed attention amid reports that Chinese hackers are waging a “cyber-spying” program against American companies.

The issue particularly hit home after high-profile hacker attacks occurred on companies such as The New York Times, Microsoft and Apple. More than 140 cyberattacks against Wall Street have reportedly occurred within the last six months.