( CNN ) -- It 's a fear that keeps cybersecurity experts up at night : an attack on an online election system . Apparently , it 's now come to pass . According to a grand jury report about problems in an August 14 , 2012 , primary election in Miami-Dade County , Florida , `` someone created a computer program that automatically , systematically and rapidly submitted to the County 's Department of Elections numerous bogus on-line requests for absentee ballots . '' It 's the first documented attack on a U.S. election , said computer scientist David Jefferson , who is on the board of the Verified Voting Foundation and the California Voter Foundation , in an interview with CNN . The report notes that 2,500 fraudulent requests were submitted . ( For perspective , Miami-Dade mailed out 139,047 absentee ballots last July and another 174,919 in October . ) With voting by mail increasing , the fact that the system was challenged is worrisome for cybersecurity experts . `` The computer scientists have been saying for many years now that this is going to be possible , and one of the counters to us has been , 'How come it has n't happened ? ' We always say , we do n't know if it 's happened , because it might happen without leaving any evidence , '' said Avi Rubin , a Johns Hopkins computer science professor who is an expert in cybersecurity . `` And now we 're finally starting to see proof that it actually does happen . '' Jefferson , who classified the attack as `` weak , '' nevertheless highlighted several reasons to be concerned . `` It 's clear that the attackers knew what they were doing , did it deliberately ( and ) tried to cover their tracks -- they were deliberately hiding their actions , '' he said . Moreover , he added , `` It is not at all clear what their motives were . '' According to the report , Miami-Dade 's online ballot request system had `` very low '' security , with no user-specific logins or passwords . A concerned election vendor noted the influx of requests and flagged them , said the report . `` The vendor hired by Election officials ... became suspicious when it appeared that an extraordinary number of absentee ballot requests 1 ) appeared to be submitted from the same group of computers ; and 2 ) were being submitted at a rate that was not humanly possible if the data on the screen was being entered by a person , '' the report said . The requests came from IP addresses primarily located overseas , the report added , `` although there was at least one fraudulent request from inside the United States . '' The grand jury report is dated December 19 , 2012 . Its findings were reported last month by the Miami Herald , although they did not receive widespread national attention until now . Florida , of course , is no stranger to electoral snafus . In 2012 alone , the state endured long lines , chaotic polling places and disputes over legislative actions that shortened the number of days and hours for early voting . But Jefferson says that , in terms of online issues , the state is far from the worst . He said he and his colleagues in the cybersecurity community found two states that had `` serious vulnerabilities '' in their online registration systems : Washington and Maryland . `` Those dangers were so severe because it would not take a lot of skill to change the registrations of thousands of voters , online , while sitting in , say , Bulgaria , '' he said . With hackers getting increasingly sophisticated , Rubin expects there will be more cyberattacks in the future . Indeed , even putting elections aside , reports of denial-of-service attacks , stolen passwords and other cases of Internet invasion are regular occurrences in the news -- and they 've affected major corporations , government agencies and even security companies , Jefferson observes . That does n't mean we have to revert back to dropping paper ballots in an old wooden box . Rubin believes that election authorities `` do a pretty good job at understanding their threats . '' It 's just that voting is such a sensitive issue that they should have to plan for the worst -- and be prepared to handle it . `` The first thing to do is have a realistic understanding of the threat , so that before you offer a service on the Internet you know how you 're going to respond when you 're attacked -- and I say 'when ' and not 'if ' you 're attacked , '' he said . Indeed , Jefferson hopes that the Miami-Dade report serves as a wake-up call for authorities who have scoffed at computer scientists ' concerns . `` For me , of course , this is no surprise . I 've seen this and much worse in many circumstances , '' he said . `` But because this is the first real documented attack in a U.S. election , it has outsized importance . We can now say we do have an example in a U.S. election of a bona fide cyberattack . You do n't have to believe us -- we did n't write that grand jury report . Read it . '' Cyberthreats getting worse , House intelligence officials warn . Alan Brill , senior managing director for Kroll Advisory Solutions , is optimistic that the wake-up call will be received promptly . `` If you look back , 20 , 25 years , ( legislators ) had no real understanding of computers . But over time , it 's kind of a rising tide '' of comprehension , he says . `` As you get more specialists in a field like this , I think the risks become more evident , and it becomes more urgent for them to do something about it . ''
A grand jury report outlines problems in an August 14 , 2012 , primary election in Florida . Someone created a computer program that made 2,500 bogus requests for absentee ballots . It 's the first documented attack on a U.S. election , said computer scientist David Jefferson . Jefferson : `` It 's clear that the attackers knew what they were doing ''