By Ellen Nakashima, The Washington Post Hackers targeted voter registration systems in Illinois and Arizona, and the FBI alerted Arizona officials in June that Russian hackers were behind the assault on the election system in that state. The bureau told Arizona officials that the threat was “credible” and severe, ranking as “an 8 on a scale of 1 to 10,” said Matt Roberts, a spokesman for the secretary of state’s office. As a result, Secretary of State Michele Reagan shut down the state voter registration system for almost a week. It turned out that the hackers did not succeed in compromising the state system or even any county system, but rather had managed to steal the user name and password for one Gila County elections official. Related ArticlesAugust 29, 2016 FBI warns of possible state election-system hacks August 25, 2016 Apple boosts iPhone security after Mideast spyware discovery August 16, 2016 Banner Health faces lawsuits after security breach August 15, 2016 Hotels in 10 states, including Colorado, and D.C.