The Christian Science Monitor 
Oct 27, 2012
Rapid advances in the development of cyberweapons and malicious software mean that electronic-voting machines used in the 2012 election could be hacked, potentially tipping the presidential election or a number of other races.
Since the machines are not connected to the Internet, any hack would not be a matter of someone sneaking through cyberspace to change ballots. Rather, the concern is that an individual hacker, a partisan group, or even a nation state could infect voting machines by gaining physical access to them or by targeting the companies that service them.
The 2010 discovery of the Stuxnet cyberweapon, which used a thumb drive to attack Iran’s nuclear facilities and spread among its computers, illustrated how one type of attack could work. Most at risk are paperless e-voting machines, which don’t print out any record of votes, meaning the electronically stored results could be altered without anyone knowing they had been changed.